Acute generalized exanthematous pustulosis. Analysis of 63 cases

IL-36-driven pustulosis: Transcriptomic signatures match between generalized pustular psoriasis (GPP) and acute generalized exanthematous pustulosis (AGEP)

BACKGROUND

Due to similarities, the distinction between generalized pustular psoriasis (GPP) and acute generalized exanthematous pustulosis (AGEP) has been a matter of debate for a long time.

OBJECTIVES

Our aim was to define the molecular features of GPP and AGEP.

METHODS

We analyzed skin biopsy samples and clinical data from 125 patients with AGEP, GPP, palmoplantar pustulosis (PPP), plaque psoriasis (PSO), and nonpustular cutaneous adverse drug reactions (ADRs), as well as from healthy skin controls using RNA-sequencing and blinded histopathologic analyses.

RESULTS

The transcriptome and histopathologic features of AGEP and GPP samples exhibited significant overlap (177 differentially expressed genes [DEGs] in GPP and AGEP compared to healthy skin, only 2 DEGs comparing AGEP and GPP). Yet, they displayed marked differences from those of PPP, PSO, and ADR samples, with a notable number of DEGs (131 DEGs comparing AGEP and PSO, 75 DEGs comparing AGEP and PPP, and 52 DEGs comparing AGEP and ADR). A transcriptome profile subgroup evaluation of >13,000 analyzed genes did not reveal any DEGs in drug-induced GPP and AGEP. Moreover, the immune response pattern and immune cell composition did not differ between drug-induced GPP and AGEP, whereas non-drug-induced GPP had higher expression of TH17-cell-related genes and a higher neutrophil count than AGEP.

CONCLUSIONS

We propose that AGEP is a drug-induced variant of GPP and therefore part of IL-36-related pustulosis. A key signature overarching this spectrum was identified, thereby opening the therapeutic approach of IL-36 inhibition to all subtypes of the disease.

Acute Generalized Exanthematous Pustulosis Induced by Hyaluronic Acid Knee Injection: A Case Report

Acute generalized exanthematous pustulosis is a severe cutaneous adverse reaction characterized by the rapid onset of nonfollicular, sterile pustules on an erythematous base, typically accompanied by fever (≥38 °C), neutrophilia (7.0 × 10⁹/L), and characteristic histopathological features. This case report presents the first documented instance of acute generalized exanthematous pustulosis after hyaluronic acid viscosupplementation. A 61-year-old female developed a pruritic, erythematous rash that rapidly evolved into generalized erythroderma with systemic manifestations after receiving intra-articular hyaluronic acid injections for knee osteoarthritis. Initial physical examination and diagnostic workup, including biopsy and blood tests, were performed to exclude other differential diagnoses such as generalized pustular psoriasis, subcorneal pustular dermatosis, and immunoglobulin A pemphigus. The temporal association with hyaluronic acid injections and the patient's positive response to treatment with systemic corticosteroids and antihistamines supported the definitive diagnosis of drug-induced acute generalized exanthematous pustulosis. The patient was managed with the withdrawal of the offending agent, and supportive care was provided. She did not require rehabilitation and experienced no adverse events during the recovery period. Follow-up visits confirmed the absence of recurrence and complete resolution of symptoms, with no lasting sequelae. This case underscores the importance of recognizing acute generalized exanthematous pustulosis' acute manifestations and potential triggers, even with treatments generally considered safe. ED personnel, including advanced practice registered nurses and other clinicians, must include acute generalized exanthematous pustulosis in their differential diagnoses of severe cutaneous disorders to initiate prompt and appropriate management. The development of atrial fibrillation during hospitalization in this patient raises questions about the systemic effects of acute generalized exanthematous pustulosis, suggesting an area for further research. Early detection and treatment of acute generalized exanthematous pustulosis are crucial for favorable outcomes, illustrating the vital role ED personnel play in managing this condition. Awareness of rare triggers such as hyaluronic acid is essential for preventing and effectively treating such severe adverse reactions.

Acute generalized exanthematous pustulosis: Analysis of cases managed in a Tunisian tertiary hospital

Acute generalized exanthematous pustulosis (AGEP) is a severe and life-threatening cutaneous adverse reaction. Drug-induced AGEP is mainly related to antibiotics. More recently, AGEP following spider bites has been increasingly described. Treatment includes withdrawal of the offending drug and supportive care. In Tunisia, data concerning severe cutaneous adverse reactions (SCARs) in general and especially AGEP is lacking. Herein, we conducted a retrospective study to investigate the epidemiological, clinical characteristics and etiologies of AGEP referred to the Dermatology department. Our study included 32 cases of AGEP. AGEP cases occurred in overall 8.9% of all SCARs referred to the department during the same period study. The majority were females (24 women and 7 men). The median age of the patients was 33 years. A history of psoriasis was reported in 16.1% of patients. All patients presented with an extensive erythematous rash with pinhead pustules. Neutrophil hyperleukocytosis (greater than 7000/mm3) was noted in 17 patients (63% of cases). It was associated with hypereosinophilia exceeding 500 elements/mm3 in 8 cases (29.6%). Drug-induced AGEP was reported in 53% of cases. Antibiotics were implicated in the majority of cases. Delay in onset ranged from 15hours to 7 days, with an average of 2.8 days. A non-drug-induced etiology was considered if the pharmacological investigation was negative, or if a clear non-drug trigger was found. It was retained in ten cases (48.4% of all observations). Spider bites were revealed in 8 cases. AGEP represents a severe, usually drug-related skin reaction. It is classified as a type IVd reaction mediating T cell-related sterile neutrophilic inflammatory response. It typically occurs within 24-48 h of ingestion of the offending drug. Antibiotics are the most common drug family to cause AGEP. Spider bites were involved in 25.8% of cases in our study, as important as antibiotic-induced AGEP. Analysis of the particularities of AGEP according to etiology, whether drug-induced or not, revealed the presence of an initial escarotic lesion (P=0.01) and the finding of blood hypereosinophilia (P=0.014) in the non-drug AGEP group were the distinguishing features. Blood hyperesoniophilia, more frequent in the non-drug AGEP group, suggests a pathophysiology probably different from that of the drug AGEP group. Clinicians should be aware of both etiologies. Our study focuses on the importance of AGEP associated with spider bite as a potential triggering factor in Tunisia.

Severe cutaneous adverse reactions

Severe cutaneous adverse reactions (SCARs), which include Stevens-Johnson syndrome and toxic epidermal necrolysis, drug reaction with eosinophilia and systemic symptoms (also known as drug-induced hypersensitivity syndrome), acute generalized exanthematous pustulosis, and generalized bullous fixed drug eruption, are life-threatening conditions. The pathogenesis of SCARs involves T cell receptors recognizing drug antigens presented by human leukocyte antigens, triggering the activation of distinct T cell subsets. These cells interact with keratinocytes and various immune cells, orchestrating cutaneous lesions and systemic manifestations. Genetic predisposition, impaired drug metabolism, viral reactivation or infections, and heterologous immunity influence SCAR development and clinical presentation. Specific genetic associations with distinct SCAR phenotypes have been identified, leading to the implementation of genetic screening before prescription in various countries to prevent SCARs. Whilst systemic corticosteroids and conventional immunomodulators have been the primary therapeutic agents, evolving strategies, including biologics and small molecules targeting tumour necrosis factor, different cytokines, or Janus kinase signalling pathways, signify a shift towards a precision management paradigm that considers individual clinical presentations.

Cutaneous adverse drug reactions

Cutaneous adverse drug reactions (ADRs) represent a heterogeneous field including various clinical patterns without specific features suggesting drug causality. Maculopapular exanthema and urticaria are the most common types of cutaneous ADR. Serious cutaneous ADRs, which may cause permanent sequelae or have fatal outcome, may represent 2% of all cutaneous ADR and must be quickly identified to guide their management. These serious reactions include bullous manifestations (epidermal necrolysis i.e. Stevens-Johnson syndrome and toxic epidermal necrolysis), drug reaction with eosinophilia and systemic symptoms (DRESS) and acute generalized exanthematous pustulosis (AGEP). Some risk factors for developing cutaneous ADRs have been identified, including immunosuppression, autoimmunity or genetic variants. All drugs can cause cutaneous ADRs, the most commonly implicated being antibiotics (especially aminopenicillins and sulfonamides), anticonvulsants, allopurinol, antineoplastic drugs, non-steroidal anti-inflammatory drugs and iodinated contrast media. Pathophysiology is related to immediate or delayed "idiosyncratic" immunologic mechanisms, i.e., usually not related to dose, and pharmacologic/toxic mechanisms, commonly dose-dependent and/or time-dependent. If an immuno-allergic mechanism is suspected, allergological explorations (including epicutaneous patch testing and/or intradermal test) are often possible to clarify drug causality, however these have a variable sensitivity according to the drug and to the ADR type. No in vivo or in vitro test can consistently confirm the drug causality. To determine the origin of a rash, a logical approach based on clinical characteristics, chronologic factors and elimination of differential diagnosis (especially infectious etiologies) is required, completed with a literature search. Reporting to pharmacovigilance system is therefore essential both to analyze drug causality at individual level, and to contribute to knowledge of the drug at population level, especially for serious cutaneous ADRs or in cases involving newly marketed drugs.

Generalized pustular psoriasis: practical recommendations for Spanish primary care and emergency physicians

Generalized pustular psoriasis (GPP) is a rare chronic inflammatory skin disease that can lead to life-threatening complications and require emergency medical treatment. Recurrent GPP flares are characterized by the sudden onset of widespread erythematous skin rash with sterile pustules, at times associated with fever, chills, general malaise, and other systemic inflammatory manifestations. Systemic complications such as cardiorespiratory failure, infections, and sepsis are potentially life-threatening and can result in an emergency department visit and/or hospitalization. Acute GPP episodes can be difficult to recognize and diagnose. The low incidence of the disease, its relapsing nature, the unpredictability of flare onset, and the lack of standardized diagnostic criteria are major obstacles to achieving rapid recognition and diagnosis in both the emergency department and the hospital setting.There is scarce evidence supporting the efficacy and safety of treatments commonly used for GPP; consequently, there is an unmet need for therapies that specifically target the condition. Our aim is to present a multidisciplinary approach to GPP to achieve a rapid diagnosis ensuring that the patient receives the most appropriate treatment for their pathology. The main recommendation for primary care and emergency physicians is to contact a dermatologist immediately for advice or to refer the patient when GPP or a flare is suspected.

Drug Hypersensitivity Reactions

Drug hypersensitivity reactions are a diverse group of reactions mediated by the immune system after exposure to a drug. The Gell and Coombs classification divides immunologic DHRs into 4 major pathophysiologic categories based on immunologic mechanism. Anaphylaxis is a Type I hypersensitivity reaction that requires immediate recognition and treatment. Severe cutaneous adverse reactions (SCARs) are a group of dermatologic diseases that result from a Type IV hypersensitivity process and include drug reaction with eosinophilia and systemic symptom (DRESS) syndrome, Stevens-Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN), and acute generalized exanthematous pustulosis (AGEP). Other types of reactions are slow to develop and do not always require rapid treatment. Emergency physicians should have a good understanding of these various types of drug hypersensitivity reactions and how to approach the patient regarding evaluation and treatment.

The Role of Sex and Gender in Dermatology - From Pathogenesis to Clinical Implications

BACKGROUND

Sex and gender have increasingly been recognized as significant risk factors for many diseases, including dermatological conditions. Historically, sex and gender have often been grouped together as a single risk factor in the scientific literature. However, both may have a distinct impact on disease incidence, prevalence, clinical presentation, severity, therapeutic response, and associated psychological distress.

OBJECTIVES AND PROJECT DESCRIPTION

The mechanisms that underlie differences in skin diseases between males, females, men, and women remain largely unknown. The specific objectives of this review paper are:To highlight the biological differences between males and females (sex), as well as the sociocultural differences between men and women (gender) and how they impact the integumentary system.To perform a literature review to identify important sex- and gender-related epidemiological and clinical differences for various skin conditions belonging to a range of disease categories and to discuss possible biological and sociocultural factors that could explain the observed differences.To discuss dermatological skin conditions and gender-affirming treatments within the transgender community, a population of individuals who have a gender identity which is different than the gender identity they were assigned at birth.

FUTURE IMPACT

With the rising number of individuals that identify as non-binary or transgender within our increasingly diverse communities, it is imperative to recognize gender identity, gender, and sex as distinct entities. By doing so, clinicians will be able to better risk-stratify their patients and select treatments that are most aligned with their values. To our knowledge, very few studies have separated sex and gender as two distinct risk factors within the dermatology literature. Our article also has the potential to help guide future prevention strategies that are patient-tailored rather than using a universal approach.

A Case of Acute Generalized Exanthematous Pustulosis Induced by Ceftriaxone

Acute generalized exanthematous pustulosis (AGEP) is a rare and severe skin disorder induced in more than 90% of cases by an adverse drug reaction. This condition is defined by an acute growth of numerous, pin-head-sized, non-follicular pustules on a background of edematous erythema that starts on the face or in the armpits and groin. It is accompanied by fever and increased inflammatory markers. We present a case of a 39-year-old male, admitted to the internal medicine department due to Streptococcus pneumoniae meningitis treated with ceftriaxone, who developed erythema covered with small sterile pustules in the face, neck, and axilla four days after antibiotic treatment. The clinical and pathological correlations confirmed the diagnosis, and the dermatosis resolved after discontinuing the drug and systemic corticosteroid treatment. Early recognition of this drug-induced dermatosis is crucial for adequate treatment.

The Man of a Thousand Pustules: A Case About Acute Generalized Exanthematous Pustulosis

Acute generalized exanthematous pustulosis (AGEP) is a rare entity characterized by fever associated with the sudden appearance of erythematous lesions, on which multiple sterile, non-follicular pustules develop. We describe a case of a 44-year-old healthy male who developed fever and multiple erythematous and edematous lesions with progressive generalization to the entire body, associated with multiple small non-follicular pustules three days after having started flucloxacillin for the treatment of a furuncle. Considering the characteristics of the exanthema, fever, and association with aminopenicillin initiation, AGEP was considered. A skin biopsy revealed subcorneal and superficial epidermal pustules, with foci of spongiosis, papillary edema, and a superficial, perivascular inflammatory cell infiltrate with neutrophils and eosinophils, consistent with the clinical diagnosis of AGEP. The culprit drug was suspended, and prednisolone was started, considering the rash extension, with progressive and complete improvement. Although it is a rare condition, the hypothesis of AGEP should be considered in acute febrile conditions with disseminated pustules. It resolves spontaneously after discontinuation of the offending drug, and the diagnosis is based on clinical presentation and skin biopsy.

Annular drug eruptions

Cutaneous adverse drug reactions are undesirable cutaneous changes caused by medications. Drug eruptions can mimic a wide range of dermatoses that include exanthematous (morbilliform), urticarial, pustular, bullous, papulosquamous, or granulomatous lesions, and sometimes these eruptions may present with annular, polycyclic, or polymorphous configurations. The correct identification of a cutaneous drug eruption depends on a high index of suspicion, detailed medication exposure history, chronologic evaluation of the causal relationships between drug exposures and eruptions, and the exclusion of other infectious or idiopathic diseases. Most drug eruptions are annoying but self-limited, usually resolving after the withdrawal of the causative agents. Rarely, patients have severe cutaneous adverse reactions, such as Stevens-Johnson syndrome, toxic epidermal necrolysis, and drug reaction with eosinophilia and systemic symptoms (DRESS), which are potentially lethal adverse drug reactions that involve the skin and mucous membranes and may also damage internal organs. Prompt recognition of the alarming signs of severe cutaneous adverse reactions and providing adequate treatment may thus be life-saving. We present the main clinical presentations, histopathology, possible implicated medications, and treatment of cutaneous adverse drug reactions that can present in annular configurations.

What to expect when AGEP is induced by terbinafine? case report and critical review of the literature

BACKGROUND

Acute Generalized Exanthematous Pustulosis (AGEP) is a rash with multiple sterile intraepidermal or sub corneal non-follicular pustules on edematous papules, with a sudden development and rapid evolution, triggered by drugs, vaccination, insect bites, exposure to mercury and allergens.

OBJECTIVES AND METHODS

We describe a female patient who developed extensive and abnormally prolonged AGEP following exposure to terbinafine and Sars-COV Vaccine. A detailed review of terbinafine-induced-AGEP cases was performed, with the aim of evaluating if the AGEP criteria would follow a different pattern when the disease is triggered by this drug. A pubmed search helped retrieve all terbinafine induced AGEP case reports. AGEP specific Sideroff criteria were analyzed in Terbinafine-induced cases, and compared to other trigger causes.

CONCLUSIONS

when AGEP causative drug was terbinafine, a delay in recovery was observed, compared to the existing AGEP criteria when other causes are considered. Terbinafine frequently leads to delayed resolution AGEP probably due to the presence of the drug in the skin during several weeks after exposure, even after discontinuation, and the disease severity may be potentialized by additional factors such as concomitant viral infections or vaccination.

Recognizing Drug Hypersensitivity in Pigmented Skin

The imagery of pigmented skin is underrepresented in teaching materials such as textbooks, journals, and online references, and this has resulted in poorer diagnostic and management outcomes of skin pathology, including delayed cutaneous drug hypersensitivity reactions. In this review, we use clinical images to highlight factors that impact clinical presentations and sequelae of drug hypersensitivity reactions in pigmented skin compared with nonpigmented skin. We describe clinical features in some anatomic sites that aid diagnosis or are associated with more severe sequelae. Finally, we discuss strategies that may aid the diagnosis and management of these reactions in pigmented skin.

Clinical Characteristics, Disease Course, and Outcomes of Patients With Acute Generalized Exanthematous Pustulosis in the US

Importance

Acute generalized exanthematous pustulosis (AGEP) is a rare, severe cutaneous adverse reaction associated with systemic complications. Currently available data are largely limited to small retrospective case series.

Objective

To describe the clinical characteristics, disease course, and outcomes of a heterogeneous group of patients with AGEP across the US.

Design, Setting, and Participants

A retrospective review of a case series of patients was conducted from January 1, 2000, through July 31, 2020. All 340 included cases throughout 10 academic health systems in the US were scored retrospectively using the EuroSCAR scoring system, and patients with a score corresponding to probable or definite AGEP and aged 18 years or older were included.

Main Outcomes and Measures

Patient demographic characteristics, clinical course, suspected causative agent, treatment, and short- and long-term outcomes.

Results

Most of the 340 included patients were women (214 [62.9%]), White (206 [60.6%]), and non-Hispanic (239 [70.3%]); mean (SD) age was 57.8 (17.4) years. A total of 154 of 310 patients (49.7%) had a temperature greater than or equal to 38.0 °C that lasted for a median of 2 (IQR, 1-4) days. Of 309 patients, 263 (85.1%) developed absolute neutrophilia and 161 patients (52.1%) developed either absolute or relative eosinophilia. Suspected causes of AGEP were medications (291 [85.6%]), intravenous contrast agents (7 [2.1%]), infection (3 [0.9%]), or unknown (39 [11.5%]). In 151 cases in which a single medication was identified, 63 (41.7%) were β-lactam antimicrobials, 51 (33.8%) were non-β-lactam antimicrobials, 9 (6.0%) were anticonvulsants, and 5 (3.3%) were calcium channel blockers. The median time from medication initiation to AGEP start date was 3 (IQR, 1-9) days. Twenty-five of 298 patients (8.4%) had an acute elevation of aspartate aminotransferase and alanine aminotransferase levels, with a peak at 6 (IQR, 3-9) days. Twenty-five of 319 patients (7.8%) experienced acute kidney insufficiency, with the median time to peak creatinine level being 4 (IQR, 2-5) days after the AGEP start date. Treatments included topical corticosteroids (277 [81.5%], either alone or in combination), systemic corticosteroids (109 [32.1%]), cyclosporine (10 [2.9%]), or supportive care only (36 [10.6%]). All-cause mortality within 30 days was 3.5% (n = 12), none of which was suspected to be due to AGEP.

Conclusions and Relevance

This retrospective case series evaluation of 340 patients, the largest known study cohort to date, suggests that AGEP onset is acute, is usually triggered by recent exposure to an antimicrobial, may be associated with liver or kidney complications in a minority of patients, and that discontinuation of the triggering treatment may lead to improvement or resolution.

Drug Triggers and Clinic of Acute Generalized Exanthematous Pustulosis (AGEP): A Literature Case Series of 297 Patients

Acute generalized exanthematous pustulosis (AGEP) is a rare skin reaction, commonly caused by drugs. Available evidence mostly relies on small studies or case reports. We collected published AGEP case reports and, subsequently, described the patient characteristics, suspect and concomitant drugs, time to onset, disease management, and clinical prognosis. This study included 297 AGEP patients (64.3% women) obtained from 250 published case reports or case series with individual patient data. AGEP affected patients of all ages, but the majority of patients (88.2%) were ≥25 years old. The most frequently reported suspect drugs were anti-infectives for systemic use (36.5%), particularly antibacterials for systemic use (31.0%), and especially beta-lactam antibacterials (18.3%) and macrolides (4.3%). Other frequent suspect drugs were antineoplastics (12.2%), and anti-inflammatory/anti-rheumatic products (5.2%) plus hydroxychloroquine (12.8%). Mean time to onset was 9.1 days (standard deviation SD 13.94). Some patients developed fever (64.3%) and systemic involvement (18.9%), and most patients (76.4%) received pharmacological treatment for AGEP. Seven patients died, although five of them were already critically ill prior to AGEP. In conclusion, antibiotics remain the most common suspected cause of AGEP. While case mortality rate may be up to 2.5%, disentangling the role of AGEP on the fatal outcome from the role of the preexisting health conditions remains challenging.

Acute localized exanthematous pustulosis because of cefixime in a child: case report and review of pediatric cases

BACKGROUND

Acute localized exanthematous pustulosis (ALEP), a localized variant of acute generalized exanthematous pustulosis, is characterized by pin-sized, non-follicular, sterile pustules that typically appear on the face, neck, and chest.

OBJECTIVE

The purpose of this report is to describe a case of ALEP in an 11-year-old girl because of cefixime and the etiological factors and clinical presentation of ALEP in pediatric group.

METHODS

We described a case of ALEP in an 11-year-old girl because of cefixime; a systematic review of the literature was performed to identify the etiological factors and clinical presentation of ALEP in children.

RESULTS

We identified eight pediatric cases with ALEP. The causative agent was an herbal product in six cases, and pustular eruption was located on the face. In two cases, responsible agents were drugs (lamotrigine and amoxicillin-clavulanic acid). The eruptions were localized on the penis and extremities, respectively.

CONCLUSION

ALEP is very rare in the pediatric age group, and topical/systemic drugs or herbal products may be involved in the etiology.

Clinical characteristics and management of acute generalized exanthematous pustulosis with haemodynamic instability

Background

Acute generalized exanthematous pustulosis (AGEP) is a severe pustular drug eruption with rare reports of haemodynamic instability.

Objective

To describe the clinical characteristics, management, and outcomes of patients with AGEP‐associated haemodynamic instability.

Methods

This retrospective case series identified adult patients diagnosed with AGEP who had haemodynamic instability from November 2012 to February 2020 that were seen at two academic teaching hospitals with roles as a burn centre and tertiary referral centre at the University of Texas Southwestern Medical Center in Dallas, TX USA. Patients with a discharge diagnosis of AGEP that had haemodynamic instability during their eruption were included. Patients with a history of psoriasis, presentations thought to be a flare of generalized pustular psoriasis, or concurrent infection during eruption were excluded. AGEP with haemodynamic instability was characterized by degree of hypotension, dermatologic phenotype at time of dermatologic consultation, and management approach.

Results

This study included 19 patients with AGEP‐associated haemodynamic instability (mean age, 52 years; age range, 29–76 years; 11 (58%) female). Patients were classified on a spectrum of haemodynamic instability; three had sustained hypotension, 10 had hypotension with organ dysfunction, and six had shock. Patients with AGEP‐associated haemodynamic instability had a range of dermatologic phenotypes at initial consultation: subtle exanthematous eruption with minimal pustules, typical eruption with pustules and flexural predominance, and severe eruption with features of Stevens–Johnson syndrome. Both topical and systemic corticosteroids were used for treatment of several patients. Of the patients that required vasopressors and received systemic steroids, the majority were off vasopressors within 24 h of steroid initiation.

Conclusion

Approximately 22% of patients presenting with AGEP to a tertiary referral center had haemodynamic instability. Clinicians should be aware that dermatologic phenotype of AGEP at presentation does not correlate with development of haemodynamic instability.

Pustular Psoriasis: From Pathophysiology to Treatment

Pustular psoriasis (PP) is a clinicopathological entity encompassing different variants, i.e., acute generalized PP (GPP), PP of pregnancy (impetigo herpetiformis), annular (and circinate) PP, infantile/juvenile PP, palmoplantar PP/palmoplantar pustulosis, and acrodermatitis continua of Hallopeau (ACH), which have in common an eruption of superficial sterile pustules on an erythematous base. Unlike psoriasis vulgaris, in which a key role is played by the adaptive immune system and interleukin (IL)-17/IL-23 axis, PP seems to be characterized by an intense inflammatory response resulting from innate immunity hyperactivation, with prominent involvement of the IL-36 axis. Some nosological aspects of PP are still controversial and debated. Moreover, owing to the rarity and heterogeneity of PP forms, data on prognosis and therapeutic management are limited. Recent progresses in the identification of genetic mutations and immunological mechanisms have promoted a better understanding of PP pathogenesis and might have important consequences on diagnostic refinement and treatment. In this narrative review, current findings in the pathogenesis, classification, clinical features, and therapeutic management of PP are briefly discussed.

Drug Hypersensitivity Reactions

Drug hypersensitivity reactions are a diverse group of reactions mediated by the immune system after exposure to a drug. The Gell and Coombs classification divides immunologic DHRs into 4 major pathophysiologic categories based on immunologic mechanism. Anaphylaxis is a Type I hypersensitivity reaction that requires immediate recognition and treatment. Severe cutaneous adverse reactions (SCARs) are a group of dermatologic diseases that result from a Type IV hypersensitivity process and include drug reaction with eosinophilia and systemic symptom (DRESS) syndrome, Stevens-Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN), and acute generalized exanthematous pustulosis (AGEP). Other types of reactions are slow to develop and do not always require rapid treatment. Emergency physicians should have a good understanding of these various types of drug hypersensitivity reactions and how to approach the patient regarding evaluation and treatment.

A Network Analysis of Drug Combinations Associated with Acute Generalized Exanthematous Pustulosis (AGEP)

Acute generalized exanthematous pustulosis (AGEP) is a rare skin adverse drug reaction. The pathophysiology and causative drugs associated with AGEP are poorly understood, with the majority of studies in AGEP focusing on a single-drug-outcome association. We therefore aimed to explore and characterize frequently reported drug combinations associated with AGEP using the WHO pharmacovigilance database VigiBase. In this explorative cross-sectional study of a pharmacovigilance database using a data-driven approach, we assessed individual case safety reports (ICSR) with two or more drugs reported to VigiBase. A total of 2649 ICSRs reported two or more drugs. Cardiovascular drugs, including antithrombotics and beta-blockers, were frequently reported in combination with other drugs, particularly antibiotics. The drug pair of amoxicillin and furosemide was reported in 57 ICSRs (2.2%), with an O/E ratio of 1.3, and the combination of bisoprolol and furosemide was recorded 44 times (1.7%), with an O/E ratio of 5.5. The network analysis identified 10 different communities of varying sizes. The largest cluster primarily consisted of cardiovascular drugs. This data-driven and exploratory study provides the largest real-world assessment of drugs associated with AGEP to date. The results identify a high frequency of cardiovascular drugs, particularly used in combination with antibiotics.

Infectious exanthemas in childhood

Most childhood exanthemas are harmless. However, recognizing serious diseases with life-threatening complications at an early stage is important for the timely initiation of adequate therapy. This requires knowledge of the specific patterns of the exanthema, obtained from the medical history and the clinic, including the patient's general condition and physical examination. In unclear cases, additional diagnostic measures are undertaken, such as blood tests and smears (cutaneous, mucocutaneous). Viruses are the most common cause of childhood exanthemas. New variants of infectious agents, improved diagnostics and stays in tropical and subtropical countries have expanded the spectrum of infectious exanthemas.

Acute localized exanthematous pustulosis: Clinical features, pathophysiology, and therapy

Acute localized exanthematous pustulosis (ALEP) is a rare disease characterized by the acute onset of multiple localized non-follicular, pinhead-sized pustules. ALEP is considered a localized form of acute generalized exanthematous pustulosis but its pathogeny is not well identified. We performed a systematic review of the literature of all publications regarding ALEP cases using the term "acute localized exanthematous pustulosis," to provide an update on this disease and its management. Results and conclusion ALEP is an uncommon skin condition attributed primarily to a hypersensitivity reaction to a systemic drug (classical or herbal); though a contact mechanism has been reported. It may be misdiagnosed as infectious or inflammatory disease but the clinico-pathological correlation in addition to the rapid response to withdrawal of the culprit agent supports this diagnosis. The pathogenesis of ALEP is still unclear, and there are no standardized treatment guidelines to manage this disease. Both AGEP and ALEP have a good prognosis if an early diagnosis is made.

The Emerging Role of the Innate Immune Response in Idiosyncratic Drug Reactions

Idiosyncratic drug reactions (IDRs) range from relatively common, mild reactions to rarer, potentially life-threatening adverse effects that pose significant risks to both human health and successful drug discovery. Most frequently, IDRs target the liver, skin, and blood or bone marrow. Clinical data indicate that most IDRs are mediated by an adaptive immune response against drug-modified proteins, formed when chemically reactive species of a drug bind to self-proteins, making them appear foreign to the immune system. Although much emphasis has been placed on characterizing the clinical presentation of IDRs and noting implicated drugs, limited research has focused on the mechanisms preceding the manifestations of these severe responses. Therefore, we propose that to address the knowledge gap between drug administration and onset of a severe IDR, more research is required to understand IDR-initiating mechanisms; namely, the role of the innate immune response. In this review, we outline the immune processes involved from neoantigen formation to the result of the formation of the immunologic synapse and suggest that this framework be applied to IDR research. Using four drugs associated with severe IDRs as examples (amoxicillin, amodiaquine, clozapine, and nevirapine), we also summarize clinical and animal model data that are supportive of an early innate immune response. Finally, we discuss how understanding the early steps in innate immune activation in the development of an adaptive IDR will be fundamental in risk assessment during drug development. SIGNIFICANCE STATEMENT: Although there is some understanding that certain adaptive immune mechanisms are involved in the development of idiosyncratic drug reactions, the early phase of these immune responses remains largely uncharacterized. The presented framework refocuses the investigation of IDR pathogenesis from severe clinical manifestations to the initiating innate immune mechanisms that, in contrast, may be quite mild or clinically silent. A comprehensive understanding of these early influences on IDR onset is crucial for accurate risk prediction, IDR prevention, and therapeutic intervention.

Acute Generalized Exanthematous Pustulosis Caused by Erlotinib in a Patient with Lung Cancer

Acute generalized exanthematous pustulosis (AGEP) is a rare drug-related adverse skin reaction caused mainly by antibiotics. Erlotinib is an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) used to treat lung cancer. A 69-year-old woman with primary lung cancer (adenocarcinoma, cT3N1M1b, stage IVB) developed erythema and multiple skin pustules on her abdomen and both thighs after 7 weeks of erlotinib treatment. She also had fever and general fatigue. Histological examination of a skin biopsy specimen showed intraepidermal pustules with neutrophil and eosinophil infiltration. She was diagnosed with erlotinib-induced AGEP. AGEP resolved by erlotinib discontinuation and systemic corticosteroid treatment. The lung cancer progressed when erlotinib was discontinued, so afatinib, a second-generation EGFR-TKI, was administrated without any skin adverse effects. Afatinib successfully decreased the lung cancer, and maintained the disease stable for 1 year. Although acneiform rash was the most common skin adverse event caused by EGFR, AGEP rarely occurred. The present case also demonstrated that it is possible to switch agents, from erlotinib to afatinib, even though they have the same pharmacological effects. Although AGEP is a rare drug-related skin disorder, physicians should be aware that erlotinib may induce AGEP.

Acute generalized exanthematous pustulosis in children and adolescents in Singapore: A ten-year retrospective review

BACKGROUND

Acute generalized exanthematous pustulosis (AGEP) is a rare, severe, cutaneous adverse reaction. Although most commonly caused by drugs, it can also be triggered by infections, especially in children.

METHODS

This is a retrospective study involving children and adolescents aged 16 years or younger, diagnosed with AGEP between January 2010 and March 2020 in our tertiary pediatric hospital. Information pertaining to the patient's demographics, clinical presentation and progress, biochemical, microbiological, and histopathological investigations, treatment, and outcomes was analyzed.

RESULTS

Eight patients were diagnosed with AGEP with mean age 8.2 years (range: 1.7-16.0 years). None of the patients had a personal or family history of psoriasis. Almost all patients had fever (n = 7, 87.5%). Although all 8 patients had intercurrent illness, 5 cases were attributed to infection, while the other 3 were likely precipitated by drugs. Abnormal hematological and biochemical parameters included a raised absolute neutrophil count (mean: 11.5 × 10⁹ /L, range: 5.0-30.9 × 10⁹ /L), C-reactive protein (mean: 52.5 mg/L, range: 5.0-143.7 mg/L), and erythrocyte sedimentation rate (mean: 38.6 mm/h, range: 6-64 mm/h). All patients developed post-pustular desquamation and subsequently recovered. The mean duration from onset to cessation of acute pustulation was 5.6 days (range: 3.0-10.0 days). One patient developed a recurrent episode of AGEP.

CONCLUSION

AGEP is rare and may be more commonly caused by infections in children. The condition is self-limiting with overall good outcomes in this age-group. In cases with concomitant infection and drug use, formal allergy testing should be arranged after resolution of the infection to confirm the underlying etiology.

Hydroxychloroquine-induced acute generalized exanthematous pustulosis: a series of seven patients and review of the literature

BACKGROUND

Hydroxychloroquine (HCQ)-induced acute generalized exanthematous pustulosis (AGEP) is poorly described in the literature. The aim of our study was to characterize the clinical, laboratory, allergological, and genetic features of HCQ-induced AGEP.

METHODS

We conducted a retrospective study of patients with HCQ-induced AGEP diagnosed between 2011 and 2019. We performed molecular analysis to identify variations in the IL36RN gene. We also reviewed similar cases reported between 1991 and March 2020.

RESULTS

Seven female patients were included. The mean age was 47 years old, and the average time from HCQ start to onset of symptoms was 40 days. All patients received topical steroids with a full resolution of the rash within an average of 39 days after HCQ withdrawal. Patch tests were performed for three patients with positive results in one case. Genetic analyses were performed for three patients, and no mutation in the IL36RN gene was identified.

CONCLUSION

The latent period and the duration for resolution of HCQ-induced AGEP may be longer than with other drugs due to the metabolic characteristics of HCQ. Mutations in the IL36RN gene were not identified in our patients.

Acute generalized exanthematous pustulosis: Epidemiology, clinical course, and treatment outcomes of patients treated in an Asian academic medical center

Background

Acute generalized exanthematous pustulosis (AGEP) is a rare severe cutaneous adverse drug reaction. Although acutely patients have significant morbidity and occasional systemic involvement, the clinical course is generally self-limited. To date, there has been no consensus on treatment.

Objective

The aim of our current study was to evaluate the clinical features, drug association, treatment, and outcomes in a cohort of patients treated in an academic medical center.

Methods

A retrospective review of electronic medical records over a period of 10 years from 2009 to 2018 in a single tertiary academic medical center in Singapore was performed. Forty-three medical records with probable/definite diagnosis of AGEP were identified and analyzed for statistical significance.

Results

Drug association was identified in 93% of cases. The most frequent drug class was antibiotics, including penicillins, cephalosporins, and vancomycin. Systemic involvement was reported in 13.9% of patients. All cases of AGEP resolved with cessation of the offending drug. There was no mortality attributed to AGEP. Treatment with systemic steroid was associated with a decreased length of hospital stay (P = .035) in patients with AGEP.

Conclusion

AGEP was a self-limiting adverse drug reaction that was commonly caused by antibiotics. Although there was no difference in mortality, there was a significant reduction in the length of hospitalization with systemic corticosteroid treatment compared with that of topical corticosteroid treatment of AGEP.

Acute Generalized Exanthematous Pustulosis with Multiple Organ Failure

Acute generalized exanthematous pustulosis (AGEP) is a rare, self-limiting condition. It presents with sterile skin pustules. We present a middle-aged lady with fluid nonresponsive circulatory shock and multiple organ dysfunction secondary to AGEP.

The necessity of patch testing in determining the causative drug of AGEP

BACKGROUND

Acute Generalized Exanthematous Pustulosis (AGEP)is a rare, severe skin reactionmainly caused by medications such as antibiotics, anti fungals, Calcium channel blockers and Anti malarias. Although it resolves spontaneously in most patients, systemic corticosteroids are neededin severe cases.

AIMS

In order to determine the drug that is causing this condition, patch testing must be performed. Hydroxychloroquine is a medication that is used for the treatment of rheumatic and dermatologic conditions. And although it has been rarely seen to cause this reaction, we report a case of Hydroxychloroquine-induced (HCQ) AGEP which was confirmed by Patch testing.

PATIENTS

A woman 49 years of age with an18 month history of mild, untreated Rheumatoid Arthritis experienced an acute episode of arthritis in her right elbow. Upon going to a rheumatologist, Prednisolone 5 mg BID and HCQ 200 mg daily were administered for a 30-day period. But after only 17 days of this treatment, the patient developed generalized erythema and painful pustular eruptions. Prednisolone dosage was changedto 7.5 mg per day andHCQ was discontinued one day afterthe appearance of eruptions. The diffuse erythema started improving a week after the patient's hospitalization.Considering the factthat our patient was receiving multiple potentially causative medications, patch testing was necessary to distinguish the drug responsible for this reaction.

RESULTS

After the patch testing was done, HCQ-induced AGEP was confirmed.

CONCLUSIONS

Patch testing is the gold standard of determining the responsible drug for an AGEP reaction. It should also be kept in mind that HCQ, although rarely, can cause this condition.

Acute generalized exanthematous pustulosis with a focus on hydroxychloroquine: A 10-year experience in a skin hospital

OBJECTIVE

Acute generalized exanthematous pustulosis (AGEP) is a severe skin pustular drug reaction that can lead to life-threatening consequences. In this study, we have investigated the characteristics and outcomes of patients with AGEP in a tertiary skin hospital.

METHODS

From March 2007 to December 2019, medical records of all patients diagnosed with AGEP, were assessed. Demographic data, culprit drug, past medical history, laboratory tests, recurrence, and systemic organ involvement were all documented as well.

RESULTS

Seventy-four patients, including 54 women (73%) and 20 men (27%), with a mean age of 44.3 ± 16.5 years were evaluated. The most common comorbidities among the patients were rheumatoid arthritis and diabetes. In addition, hydroxychloroquine, cephalosporin, and amoxicillin were found as the three most common medications associated with AGEP induction. Among the study group, seventeen (23%) patients had systemic organ involvement (nine (12.2%), six (8.1%), and five (6.8%) had hepatic, renal and pulmonary involvement, respectively). All patients responded to oral prednisolone within a median of five days (IQR = 4; ranged 2-14). The median duration of treatment was significantly longer in hydroxychloroquine group compared to other drugs (8 versus 5 days; HR 0.57,95%CI 0·35-0.91). Likewise, the median duration of treatment was significantly longer in febrile patients compared to the afebrile ones (7 versus 4 days; HR 0.46, 95%CI 0.25-0.85). Recurrence occurred in six patients after resuming treatment with the same medication. The mean Naranjo score was 7.6 ± 0.9 denoting a probable causal relationship.

CONCLUSION

In this study, we found that using hydroxychloroquine and presence of fever are the risk factors potentially leading to a prolonged treatment duration of AGEP.

Clinical Presentation and Management of Atypical and Recalcitrant Acute Generalized Exanthematous Pustulosis (AGEP)

Acute generalized exanthematous pustulosis (AGEP) is a severe cutaneous adverse reaction (SCAR) characterized by sterile non-follicular pustules on an erythematous base that form rapidly after drug exposure. AGEP is mediated by numerous cytokines produced by drug specific T-cells that mediate neutrophilic intracorneal, subcorneal, and/or intraepidermal pustule development. Though genetic susceptibility is not fully understood, individuals with mutations in IL-36RN may be at increased risk of AGEP development. AGEP commonly presents with leukocytosis and fever in the acute pustular phase and follows a self-limited desquamative recovery phase upon removal of offending drug. Severe cases of AGEP may have multisystem organ involvement. Atypical presentations of AGEP include localized eruptions and cases with overlapping clinical and histopathological features associated with Stevens-Johnson syndrome/toxic epidermal necrolysis, drug reaction with eosinophilia and systemic symptoms, and generalized pustular psoriasis. Most cases of AGEP clear rapidly with systemic corticosteroids, but severe or recalcitrant cases may require other systemic therapies such as cyclosporine, and intravenous immunoglobulin.

Acute generalized exanthematous pustulosis with airway mucosa involvement: A case report

BACKGROUND

Acute generalized exanthematous pustulosis (AGEP) is a severe cutaneous adverse reaction characterized by sterile pustules on erythematous skin associated with fever and leukocytosis. The annual incidence of AGEP is estimated to be 1-5 cases per million. Cases of AGEP with oral mucosa involvement have been reported. However, reports of AGEP involving airway mucosa are limited.

CASE SUMMARY

We report a 42-year-old woman with serious AGEP involving the airway mucosa. The patient initially developed fever and a small rash on her forehead and face. Over the next 2 d, she developed a diffuse, pustular rash over her trunk and legs. In addition, she complained of a cough with white foam-like sputum, chest tightness and dyspnea. Four days later, due to dyspnea, her mental status started to gradually deteriorate. She became more and more drowsy. Biopsies of the skin and airway mucosa suggested the diagnosis of AGEP. According to the European study of severe cutaneous adverse reactions group’s scoring system, the patient scored +6 indicating a probable diagnosis of AGEP. She received intravenous methylprednisolone 120 mg/12 h for 3 d, and was eventually discharged in good condition. This patient had already experienced respiratory failure and airway mucosa involvement on admission; however, the clinicians had an insufficient understanding of AGEP. Glucocorticoid was administered for more than 10 d following onset of the disease, and her overall prognosis was satisfactory.

CONCLUSION

This case represents a rare clinical feature of AGEP and an important finding for clinicians.

Antibiotic-Impregnated Intramedullary Cement Nail-Induced Acute Generalized Exanthematous Pustulosis and Septic Shock: A Case Report

CASE

A 28-year-old woman with an infected proximal femur nonunion was treated with an antibiotic-coated intramedullary nail. Shortly after discharge, the patient presented to the emergency department and was readmitted with a morbilliform rash sparing the left lower extremity. She became hemodynamically unstable, despite cessation of intravenous antibiotics, requiring transfer to the intensive care unit and urgent removal of her antibiotic nail. She improved after surgery, and biopsy results from the rash confirmed acute generalized examthematous pustulosis.

CONCLUSION

Acute generalized exanthematous pustulosis is a rare, dermatologic crisis that can be precipitated by antibiotics, even in the form of antibiotic cement.

Neutrophilic drug reactions

Neutrophilic drug reactions are unique eruptions that can affect hospitalized patients and share a common pathophysiology with neutrophils as the key mediators of inflammation. They range in clinical presentation from papules and plaques to bullae and erosions to pustules. Although there is some overlap in presentation, each has distinguishing features that aid the clinician in differentiation from one another and from other drug hypersensitivity reactions. Much of the data on these reactions are from case reports and series or retrospective review studies. There are limited prospective observational studies dedicated to these adverse drug reactions. We review the more common and life-threatening neutrophilic drug reactions, their proposed mechanism of action, and their management.

Pharmacogenetic Testing for Prevention of Severe Cutaneous Adverse Drug Reactions

Severe cutaneous adverse reactions (SCAR), such as Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and drug rash with eosinophilia and systemic symptoms (DRESS), are idiosyncratic and unpredictable drug-hypersensitivity reactions with a high-mortality rate ranging from 10% to over 30%, thus causing a major burden on the healthcare system. Recent pharmacogenomic studies have revealed strong associations between SCAR and the genes encoding human-leukocyte antigens (HLAs) or drug-metabolizing enzymes. Some of pharmacogenetic markers have been successfully applied in clinical practice to protect patients from SCAR, such as HLA-B*15:02 and HLA-A*31:01 for new users of carbamazepine, HLA-B*58:01 for allopurinol, and HLA-B*57:01 for abacavir. This article aims to update the current knowledge in the field of pharmacogenomics of drug hypersensitivities or SCAR, and its implementation in the clinical practice.

Etiopathological and Clinical Study of Acute Generalized Exanthematous Pustulosis: Experience from a Tertiary Care Hospital in North India

Background:

Acute generalized exanthematous pustulosis (AGEP) is a type of severe cutaneous adverse reaction that is characterized by the rapid development of nonfollicular, sterile pustules on an erythematous base.

Objectives:

The aim of our study was to enroll all cases of AGEP reporting to our department over a period of one year and to find out the clinical and etiological profile of the patients.

Materials and Methods:

All the patients reporting to our department with clinical features suggestive of AGEP were enrolled for the study. Careful history and examination were done to rule out other causes of pustular eruptions, which can resemble AGEP. AGEP validation score of the EuroSCAR study group was used to establish the diagnosis.

Results:

A total of 16 patients were enrolled during the study period of one year. The majority of the patients were females with a mean age of 28.41 ± 12.2 years. Twelve (75%) of the patients had a history of drug intake while 4 (25%) had developed AGEP following an insect bite. Penicillins were the causative factor in five patients followed by cephalosporins in three patients, nonsteroidal anti-inflammatory drugs (NSAIDs) in 2 patients, and terbinafine in 1 patient. Tetanus toxoid was responsible for the development of AGEP in one patient. The insect bites were all spider bites.

Conclusion:

AGEP is a rare type of severe cutaneous adverse drug reaction.We encountered 16 patients of AGEP over a period of one year. An important cause of AGEP was spider bite in our study group.

[Neutrophilic and pustular dermatoses : New autoinflammatory diseases and syndromes]

This article reviews noninfectious inflammatory dermatoses with mainly neutrophilic infiltrates and the formation of pustules. The infiltrate containing neutrophils may either be mild as in urticaria or very dense, even with leukocytoclasia, as in Sweet syndrome or pyoderma gangrenosum. Neutrophilic infiltrates and pustular eruptions are caused by different noninfectious immunomechanisms. For some of them, mutations have been found (e.g. NLRC4 mutation in cryopyrin-associated periodic syndromes (CAPS) leading to activation of the inflammasome; IL36RN mutation in pustular psoriasis resulting in uncontrolled IL36 signaling). Neutrophilic dermatoses are of high interest, as they may be the cause of underlying benign or malignant conditions. In recent years, efficient targeted therapies have been developed.