Severe flucloxacillin-induced acute generalized exanthematous pustulosis (AGEP), with toxic epidermal necrolysis (TEN)-like features: does overlap between AGEP and TEN exist? Clinical report and review of the literature

TEN mimics: Classification and practical approach to toxic epidermal necrolysis-like dermatoses

Toxic epidermal necrolysis (TEN) is an acute life-threatening dermatologic emergency. However, many dermatoses can present with a TEN-like eruption. Those "TEN-mimics" are a true diagnostic challenge and an alarming differential diagnosis to such a serious condition. Herein, we will expose and classify the landscape of TEN-mimics. Also, the key differentiating clinical and/or laboratory points will be highlighted to help an accurate diagnosis of either a TEN or a TEN-like presentation.

Expression Profile of CD157 Reveals Functional Heterogeneity of Capillaries in Human Dermal Skin

CD157 acts as a receptor, regulating leukocyte trafficking and the binding of extracellular matrix components. However, the expression pattern and the role of CD157 in human blood (BEC) and the lymphatic endothelial cells (LEC) of human dermal microvascular cells (HDMEC), remain elusive. We demonstrated constitutive expression of CD157 on BEC and LEC, in fetal and juvenile/adult skin, in situ, as well as in isolated HDMEC. Interestingly, CD157 epitopes were mostly localized on BEC, co-expressing high levels of CD31 (CD31High), as compared to CD31Low BEC, whereas the podoplanin expression level on LEC did not affect CD157. Cultured HDMEC exhibited significantly higher numbers of CD157-positive LEC, as compared to BEC. Interestingly, separated CD157− and CD157+ HDMEC demonstrated no significant differences in clonal expansion in vitro, but they showed distinct expression levels of cell adhesion molecules, before and after cytokine stimulation in vitro. In particular, we proved the enhanced and specific adherence of CD11b-expressing human blood myeloid cells to CD157+ HDMEC fraction, using an in vitro immune-binding assay. Indeed, CD157 was also involved in chemotaxis and adhesion of CD11b/c monocytes/neutrophils in prevascularized dermo–epidermal skin substitutes (vascDESS) in vivo. Thus, our data attribute specific roles to endothelial CD157, in the regulation of innate immunity during inflammation.

Multisystem organ failure secondary to acute generalised exanthematous pustulosis (AGEP) with atypical presentation resembling septic shock

A woman was admitted for sepsis secondary to cellulitis. After clinical improvement of sepsis, non-follicular small pustules were observed on the trunk, limbs and face while vesicles/bullae and skin exfoliation were noted on upper extremities. Larger systemic manifestations included fever, hypertension and tachycardia. Laboratory results revealed neutrophilic leukocytosis, eosinophilia, mild transaminitis and acute renal failure. Despite treatment for potential sepsis and discontinuation of offending agents, her condition worsened leading to haemodynamic instability and renal failure requiring vasopressor support, intubation and continuous veno-venous haemodialysis. Skin biopsy revealed a diagnosis of acute generalised exanthematous pustulosis (AGEP), a rare condition usually caused by antibiotic treatment. The suspected offending drug was clindamycin, with possible combined effects by metronidazole and/or vancomycin. Improvement of skin manifestations were seen within 48 hours of starting systemic steroids. Here, we present an uncharacteristic case of AGEP clinically presenting with atypical skin lesions, severe systemic involvement mimicking septic shock, which culminated in multisystem organ failure.

Results of patch testing in Acute generalized exanthematous pustulosis (AGEP): a literature review

The literature on positive patch test results in acute generalized exanthematous pustulosis (AGEP) is reviewed. 93 drugs were identified that have together caused 259 positive patch tests in 248 patients suffering from AGEP. The drug classes causing the highest number of reactions are beta-lactam antibiotics (25.9%), other antibiotics (20.8%), iodinated contrast media (7.3%) and corticosteroids (5.4%), together accounting for nearly 60% of all reactions. The highest number of reactions to individual drugs was to amoxicillin (n=36), followed by pristinamycin (n=25), diltiazem (n=14), amoxicillin-clavulanic acid (n=13), clindamycin (n=11) and iomeprol (n=8); 59 of the 93 drugs each caused a single case only. The "Top-10" drugs together caused over 50% of all reactions. The sensitivity of patch testing (percentage of positive reactions) in patients with AGEP is largely unknown, but may generally be around 50%, which also applies to pristinamycin. Patch testing in AGEP appears to be safe, although mild recurrence of AGEP skin symptoms or other rashes may occur occasionally. Clinical aspects of AGEP, including epidemiology, etiology and pathophysiology, clinical features, histology, treatment, and prognosis are briefly presented, as are diagnosing the disease and identifying the culprit drugs with patch tests, intradermal tests, in vitro tests, and challenge tests. This article is protected by copyright. All rights reserved.

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.

A severe presentation of acute generalized exanthematous pustulosis with non-infectious circulatory shock in an adolescent

We present a severe case of acute generalized exanthematous pustulosis (AGEP) secondary to trimethoprim-sulfamethoxazole complicated by non-infectious circulatory shock in a 16-year-old boy. Hemodynamic instability has been reported as a complication of AGEP in adults, but is rarely observed in pediatric patients. The patient we present demonstrated characteristic cutaneous findings of AGEP including isolated non-follicular, sterile pustules on a background of erythema with involvement at intertriginous areas and subsequently developed non-infectious circulatory shock. This case expands the spectrum of possible clinical presentations for AGEP in pediatric patients.

Neutrophils initiate and exacerbate Stevens-Johnson syndrome and toxic epidermal necrolysis

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are life-threatening mucocutaneous adverse drug reactions characterized by massive epidermal detachment. Cytotoxic T cells and associated effector molecules are known to drive SJS/TEN pathophysiology, but the contribution of innate immune responses is not well understood. We describe a mechanism by which neutrophils triggered inflammation during early phases of SJS/TEN. Skin-infiltrating CD8⁺ T cells produced lipocalin-2 in a drug-specific manner, which triggered the formation of neutrophil extracellular traps (NETs) in early lesional skin. Neutrophils undergoing NETosis released LL-37, an antimicrobial peptide, which induced formyl peptide receptor 1 (FPR1) expression by keratinocytes. FPR1 expression caused keratinocytes to be vulnerable to necroptosis that caused further release of LL-37 by necroptotic keratinocytes and induced FPR1 expression on surrounding keratinocytes, which likely amplified the necroptotic response. The NETs-necroptosis axis was not observed in less severe cutaneous adverse drug reactions, autoimmune diseases, or neutrophil-associated disorders, suggesting that this was a process specific to SJS/TEN. Initiation and progression of SJS/TEN keratinocyte necroptosis appear to involve a cascade of events mediated by innate and adaptive immune responses, and understanding these responses may contribute to the identification of diagnostic markers or therapeutic targets for these adverse drug reactions.

Rare and Complicated Overlap of Stevens-Johnson Syndrome and Acute Generalized Exanthematous Pustulosis

Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) and acute generalized exanthematous pustulosis (AGEP) are two separate pathological entities of severe cutaneous adverse reactions (SCARs) with different etiologies and treatment strategies. Diagnosis is, however, complicated by the similarity in their clinical presentation. Although there are few claims of AGEP-SJS/TEN overlap, a simultaneous true overlap of SJS/TEN and AGEP has rarely been described in the literature. Here, we report a case study of a 61-year-old female with a known allergy to sulfa drugs presenting with altered mental status, generalized weakness, and erythematous and excoriated purulent wounds. Based on initial workup and extensive consultation, the patient was diagnosed with severe sepsis secondary to diffuse purulent cellulitis, community-acquired pneumonia, and acute renal failure due to prerenal azotemia from dehydration. She was treated with several antibiotics, starting with vancomycin, piperacillin/tazobactam. Six days later, antibiotics were de-escalated to ceftriaxone and metronidazole because of the patient's improved status. The medications were withheld when the patient started developing extensive blistering on day 8. Blood cultures ruled out any bacterial etiology. Skin biopsy confirmed overlapping features of AGEP and SJS/TEN. Due to the uncontrolled progression of her rash, she was transferred to the burn unit of a higher care center. This is potentially the first histologically confirmed case of AGEP-SJS/TEN overlap in the United States. In this case study, a conclusive diagnosis would have never been made without a biopsy, especially because the condition presented clinically as SJS/TEN. We, therefore, recommend considering a potential overlap of multiple pathologies at each presentation or suspicion of a SCAR and performing an early skin biopsy in order to provide definitive diagnosis and treatment.

Acute generalized exanthematous pustulosis simulating toxic epidermal necrolysis: case presentation and literature review

Background

Acute generalized exanthematous pustulosis (AGEP) and toxic epidermal necrolysis (TEN) are severe cutaneous adverse reactions. These rare conditions differ in clinical presentation, pathological features, treatment and prognosis, but overlap has been described implying a challenging clinical management.

Case presentation

We describe a case of overlap between TEN and AGEP probably secondary to beta-lactams in a 77-year-old patient treated for a complicated cholangitis. We review the diagnosis and the management of these two conditions. The diagnosis of TEN was suggested by the initial clinical presentation with severe hemodynamic instability, skin detachment, positive Nikolsky sign and mucosal involvement. However, the skin biopsy as well as the rapid improvement of the skin lesions were discriminative for AGEP. This indicated an overlap presentation. Unfortunately, the patient refused allergy investigations in order to find the culprit drug. Medical photographs, proper physical examination and histopathological results are integrated.

Conclusion

Despite clinical features indicating a diagnosis of TEN, histopathology was conclusive for AGEP thus indicating a possible clinical-pathological overlap between the two conditions, a scarcely described situation in the medical literature. To our knowledge, this is one of the few cases that portrays a TEN–AGEP overlap probably secondary to Piperacillin Tazobactam. Understanding the immunological implications of these conditions can help us better distinguish and manage these severe reactions.

Piperacillin/Tazobactam as Cause of Acute Generalized Exanthematous Pustulosis

Acute generalized exanthematous pustulosis (AGEP) is a rare cutaneous adverse reaction mainly attributed to antibiotics. It is characterized by numerous, nonfollicular, sterile pustules, arising on an exanthematous and edematous base. It is a serious adverse reaction accompanied by fever and leukocytosis. Piperacillin/tazobactam is indicated for the treatment of patients with moderate to severe infections. Herein is reported a case of AGEP caused by piperacillin/tazobactam. A 78-year-old woman with metastatic breast cancer was presented to the emergency department reporting fever and groin pain. The laboratory analysis and more specifically urine cultivation showed a urinary tract infection by E. coli with sensitivity to piperacillin/tazobactam. She had no known allergies. She was started on intravenous piperacillin/tazobactam; she improved clinically on the second day, but on the fourth day of intravenous therapy, she developed extensive pustular rash on the folds and anterior proximal thighs, accompanied by fever and neutrophilia. Piperacillin/tazobactam administration was interrupted and she was given prednisolone for ten days. The patient improved clinically and her laboratory tests returned to normal after two weeks. AGEP is an uncommon side effect of piperacillin/tazobactam treatment and there are few cases reported.

Association of non-immediate drug hypersensitivity with drug exposure: A case control analysis of spontaneous reports from a Tunisian pharmacovigilance database

PURPOSE

To assess delayed-type cutaneous reactions (DTCRs) related to drugs, using a case-control approach to qualify drug risks.

METHODS

The study used the Tunisian pharmacovigilance database of Monastir. The association between drugs and DTCRs was assessed using a case/non-case method. Drugs were grouped according to the ATC Classification System. Patients were defined as "cases" if they have developed DTCRs regardless of the causality assessment. All other reports were "non-cases". Association between reactions and drugs was calculated using the reporting odds ratio (ROR) with 95% confidence intervals (CIs). A p value < 0.05 was considered significant.

RESULTS

The analysis was carried out on 1798 reports, of which 867 concerned DTCRs (cases) and 931 concerned non-cases. The calculated risk estimates were significant for cefotaxime (ROR 2.1; 95% CI 1.5 to 3), pristinamycin (ROR 4; 95% CI 2 to 7.9), sulfamethoxazole (ROR 4.4; 95% CI 1.6 to 11.7), oxacillin (ROR 2.2; 95% CI 1.2 to 3.8), doxycycline (ROR 10.8; 95% CI 1.4 to 84.9), carbamazepine (ROR 3.3; 95% CI 1.7 to 6.2), phenobarbital (ROR 2.3; 95% CI 1.03 to 5.1), allopurinol (ROR 3.6; 95% CI 1.8 to 7.2), furosemide (ROR 2.4; 95% CI 1.3 to 6.3), hydrochlorothiazide(ROR 2.9; 95% CI 1.3 to 6.3) and candesartan (ROR 4.7; 95% CI 1.3 to 16.6).

CONCLUSION

Our findings corroborate risks for a number of drugs, such as antibacterials, antiepileptics and allopurinol in inducing DTCRs. Given the widespread use of these drug classes, awareness should be raised among patients and prescribers about these risks.

Life-Threatening Atypical Case of Acute Generalized Exanthematous Pustulosis

Antibiotics are known to cause severe cutaneous adverse reactions, such as the rare acute generalized exanthematous pustulosis (AGEP). Unlike Stevens-Johnson syndrome or toxic epidermal necrolysis, AGEP is rarely life-threatening. Systemic involvement is not typical, and if present usually coincides with a mild elevation of the hepatic enzymes and a decrease in renal function. Hence, AGEP is known to have a good prognosis and to be life-threatening only in elderly patients or patients with chronic diseases. Herein, we report a case of AGEP in a young healthy male leading to systemic inflammatory response syndrome and to treatment in an intensive care unit after being treated with 5 different antibiotics. Initial symptoms were not indicative for AGEP and the patient's course of disease led promptly to critical cardiorespiratory symptoms and systemic inflammatory response syndrome. We assume that the administration of the 5 different antibiotics resulted in type IV allergy as well as secondary infection with Enterococcus faecium and Staphylococcus aureus, while the underlying periodontitis also contributed to the severity of this case.

Adverse drug reactions and organ damage: The skin

Cutaneous adverse drug reactions are frequent, affecting 2-3% of hospitalized patients and in one twentieth of them are potentially life-threatening. Almost any pharmacologic agent can induce skin reactions, and certain drug classes, such as non-steroidal anti-inflammatory drugs, antibiotics and antiepileptics, have drug eruption rates ranging from 1% to 5%. Cutaneous drug reactions recognize several different pathomechanisms: some skin manifestations are immune-mediated like allergic reactions while others are the result of non immunological causes such as cumulative toxicity, photosensitivity, interaction with other drugs or different metabolic pathways. Cutaneous adverse drug reactions can be classified into two groups: common non-severe and rare life-threatening adverse drug reactions. Non-severe reactions are often exanthematous or urticarial whereas life-threatening reactions typically present with skin detachment or necrosis of large areas of the body and mucous membrane involvement, as in the Stevens-Johnson syndrome or toxic epidermal necrolysis. Clinicians should carefully evaluate the signs and symptoms of all cutaneous adverse drug reactions thought to be due to drugs and immediately discontinue drugs that are not essential. Short cycles of systemic corticosteroids in combination with antihistamines may be necessary for widespread exanthematous rashes, while more aggressive corticosteroid regimens or intravenous immunoglobulins associated with supportive treatment should be used for patients with Stevens-Johnson syndrome or toxic epidermal necrolysis.

Severe Cutaneous Drug Reactions: Do Overlapping Forms Exist?

Acute generalized exanthematous pustulosis, Stevens-Johnson syndrome, toxic epidermal necrolysis, and drug reaction with eosinophilia and systemic symptoms are all severe hypersensitivity reactions to medications. While each of these reactions is a well-established entity with specific diagnostic criteria, clinicians see cases that fulfill criteria for more than one form, prompting discussion on the possibility of combined forms. Such overlapping clinical pictures meeting the criteria for 2 conditions have thus become a topic of debate in dermatology in recent years. We describe 2 patients with cutaneous drug reactions having the characteristics of both acute generalized exanthematous pustulosis and Stevens-Johnson syndrome -toxic epidermal necrolysis. We also review previously published cases and current thinking on such overlapping conditions.

Towards the development of mechanism-based biomarkers to diagnose drug hypersensitivity

T-cells are activated by different mechanisms in the presence of drugs, metabolites or haptens, and they release several molecules that can be used in the diagnosis of drug hypersensitivity.