Terbinafine induced pityriasis rosea-like eruption

Clinicopathologic features of pityriasis rosea-like drug eruption secondary to imatinib: A case report and review of the literature

Pityriasis rosea is an acute, self-limited exanthem that typically occurs in adolescence and young adulthood, classically featuring ovoid erythematous and scaly lesions on the trunk and proximal extremities. While its cause is not definitively known, the classic form of pityriasis rosea may result from the reactivation of latent human herpesvirus (HHV) infections (HHV-6 and HHV-7). Interestingly, drug eruptions that clinically and/or histopathologically resemble pityriasis rosea have also been reported. These pityriasis rosea-like drug eruptions tend to occur at an older age and have a shorter duration than the classic type. As there are different management paradigms, the distinction between classic pityriasis rosea and the mimicking drug eruption is important to recognize. Herein, we report a case of a pityriasis rosea-like drug eruption that occurred in association with imatinib mesylate treatment for chronic myeloid leukemia. We also review the clinicopathologic features of reported cases of pityriasis rosea-like drug eruption, including those due to imatinib. While the clinical morphology of the cutaneous drug-related eruption mimics the lesions seen in classic pityriasis rosea, the presence of unique histopathologic findings, including necrotic keratinocytes, interface dermatitis, and eosinophils, may aid in distinction.

A Current Diagnostic and Therapeutic Challenge: Tinea Capitis

Tinea capitis is a dermatophyte scalp infection with a marked prevalence among the pediatric population. However, in the last few years, its epidemiology has changed due to increasing population migration worldwide. Host-specific and environmental factors contribute to the pathogenesis of tinea capitis. Clinically, tinea capitis may present as a subtle hair loss accompanied by scalp scaling, alopecia with scaly patches, or alopecia with black dots. A more severe form of tinea capitis is represented by kerion celsi, which clinically presents as a tender plaque covered by pustules and crusts. If left untreated, this dermatophytic infection may resolve with permanent scarring and alopecia. The pathological changes found in tinea capitis are reflected by a spectrum of clinical changes. Zoophilic infections typically prompt an extensive inflammatory reaction, while anthropophilic dermatophytoses often lack inflammation and result in more persistent lesions. Tinea capitis typically requires systemic antifungal therapy. Griseofulvin, terbinafine, itraconazole, and fluconazole are the main antifungal agents used. Currently, the duration of antifungal therapy varies based on the clinical presentation and type of dermatophyte involved. Through the reported cases and literature review, we aim to emphasize the importance of the early recognition of atypical variants of tinea capitis in immunocompetent children for the prompt initiation of systemic antifungal therapy, minimizing the need for prolonged treatment. Additionally, we emphasize the importance of regular laboratory testing during systemic antifungal therapy, particularly liver enzyme tests, to prevent adverse events, especially in cases requiring long-term treatment.

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.

Atypical pityriasis rosea in a young Colombian woman. Case report

Introduction: Pityriasis rosea is an acute and self-limited exanthemfirst described by Gilbert in 1860. Its treatment is symptomatic, and although there is no conclusive evidence, it has been associated with the reactivation of the human herpesviruses 6 and 7 (HHV-6 and HHV-7). Case presentation: A 28-year-old woman, from Bogotá, Colombia, ahealth worker, attended the emergency room due to the onset ofsymptoms that began 20 days earlier with the appearance of punctiformlesions in the left arm that later spread to the thorax, abdomen, opposite arm, and thighs. The patient reported a history of bipolar II disorder and retinal detachment. After ruling out several infectious diseases, and due to the evolution of the symptoms, pityriasis rosea was suspected. Therefore, treatment was started with deflazacort 30mg for 21 days, obtaining a favorable outcome and improvement of symptoms after 2 months. At the time of writing this case report, the patient had not consulted for recurrence. Conclusion: Primary care physicians should have sufficient training indermatology to recognize and treat dermatological diseases since manyof them are diagnosed based on clinical findings. This is an atypicalcase, in which the patient did not present with some of the pathognomonic signs associated with pityriasis rosea.

Pityriasis Rosea: An Updated Review

BACKGROUND

Pityriasis rosea is a common acute, self-limited papulosquamous dermatosis that primarily affects children and young adults. The condition and its clinical variants may pose a diagnostic challenge, especially in the absence of the herald patch.

OBJECTIVE

This article aimed to familiarize pediatricians with clinical manifestations, evaluation, diagnosis, and management of pityriasis rosea.

METHODS

A search was conducted in March 2020 in Pubmed Clinical Queries using the key term " pityriasis rosea". The search strategy included all clinical trials (including open trials, non-randomized controlled trials, and randomized controlled trials), observational studies, and reviews (including narrative reviews and meta-analyses) published within the past 10 years. Only papers published in the English literature were included in this review. The information retrieved from the above search was used in the compilation of the present article.

RESULTS

Pityriasis rosea occurs mainly in individuals between 10 and 35 years of age with a peak during adolescence. Human herpesvirus (HHV)-7 and HHV-6 have been implicated as the causative agents in some patients with pityriasis rosea. A mild prodrome consisting of headaches, fever, malaise, fatigue, anorexia, sore throat, enlarged lymph nodes and arthralgia is present in about 5% of patients. The most common presenting sign, found in approximately 80% of patients, is a "herald" or "mother" patch which is larger and more noticeable than the lesions of the later eruption. A generalized, bilateral, symmetrical eruption develops in approximately 4 to 14 days and continues to erupt in crops over the next 12 to 21 days. Typical lesions are 0.5 to 1 cm, oval or elliptical, dull pink or salmon-colored macules with a delicate collarette of scales at the periphery. The long axes tend to be oriented along the skin lines of cleavage (Langer lines). Lesions on the back may have a characteristic "Christmas tree", whereas lesions on the upper chest may have a V-shaped pattern. There are many conditions that may mimic pityriasis rosea. Pityriasis rosea in the absence of the herald patch and its variants may pose a diagnostic challenge. The typical course is 6 to 8 weeks. In the vast majority of cases, reassurance and symptomatic treatment should suffice. Active intervention may be considered for individuals with severe or recurrent pityriasis rosea and pregnant women with the disease. Treatment options include acyclovir, macrolides (in particular, erythromycin), and ultraviolet phototherapy. If active intervention is needed, there is evidence supporting the use of oral acyclovir to shorten the duration of illness.

CONCLUSION

Pityriasis rosea is a common, acute, self-limiting exanthematous skin disease that primarily affects children and young adults. The condition is characterized by a "herald patch" after which oval erythematous squamous lesions appear along Langer's lines of cleavage on the trunk and proximal extremities, giving it a "Christmas tree" appearance. The disease presenting in its classical form can easily be diagnosed. Clinical variants of the disease may pose a diagnostic challenge for the general pediatrician. Knowledge of the disease is essential to allow prompt diagnosis and to avoid unnecessary investigations.

A review of the traditional use of southern African medicinal plants for the treatment of fungal skin infections

ETHNOPHARMACOLOGICAL RELEVANCE

Human dermatophyte infections are one of the most common classes of infection globally, with an estimated 1.7 billion people contracting at least one infection annually. Southern African ethnic groups used multiple plants to treat dermatophytosis and to alleviate the symptoms, yet the anti-dermatophyte properties of most species remain poorly explored.

AIM OF THE STUDY

Our study aimed to critically review the literature to document southern African plant species used to treat one or more dermatophytic infections, and to summarise scientific evaluations of these and other plant species. Our study aims to stimulate and focus future studies in this field.

MATERIALS AND METHODS

A thorough review of the ethnobotanical books, reviews and primary scientific studies were undertaken to identify southern African plants used traditionally to treat dermatophytosis, thereby identifying gaps in the research requiring further study.

RESULTS

Eighty-nine southern African plant species are recorded as traditional therapies for dermatophytosis. Scientific evaluations of 140 plant species were identified, although most of the species in those studies were selected for reasons apart from their traditional uses. None of those studies examined the mechanism of action of the plant species, and only a single study screened the extracts for toxicity.

CONCLUSIONS

Despite southern Africa having some of the longest continuous human civilisations globally, as well as unique and diverse flora, and good ethnobotanical records, the anti-dermatophyte properties of southern African medicinal plants remains relatively poorly explored. The efficacy of the majority of plants used traditionally to treat fungal skin disease are yet to be verified and substantial further research is required in this field.

Oral Antifungal Therapy: Emerging Culprits of Cutaneous Adverse Drug Reactions

Introduction

Antifungals are one of the most widely used drugs in dermatology practice for dermatophytosis. Oral antifungal therapy against superficial dermatophytosis is generally associated with a low incidence of adverse events in an immunocompetent population. However, lately, cutaneous adverse drugs reactions (CADRs) have been reported with varying incidence rates in the patients on oral antifungal therapy with many uncommon morphological patterns. The present, observational study was conducted over a period of 4 months to report the cases which presented with antifungal therapy-associated CADRs.

Materials and Methods

It was an observational, prospective study carried out at a tertiary care center in Western India over a period of 4 months. All patients diagnosed with superficial dermatophytic infections (clinically and fungal hyphae seen on 10% potassium hydroxide mount) started on oral antifungal therapy, presenting with cutaneous manifestation other than the primary dermatophytosis were included. The incidence of CADRs due to oral antifungal agents and the percentage of each clinical type of the CADR observed was calculated.

Results

The incidence of CADRs due to antifungal drugs was 8.3 per 10,000 patients. In total, 35 cases were reported out of 4,208 cases of dermatophytosis. Terbinafine was the most common causative drug, accounting for nearly 83% of cases, followed by itraconazole for 14% cases, and griseofulvin for 2.8% of cases.

Conclusion

The role of systemic antifungals must not be overlooked in any patient with a CADR and should be reported as a trend indicator.

CYP2C19 and 3A4 Dominate Metabolic Clearance and Bioactivation of Terbinafine Based on Computational and Experimental Approaches

Lamisil (terbinafine) is an effective, widely prescribed antifungal drug that causes rare idiosyncratic hepatotoxicity. The proposed toxic mechanism involves a reactive metabolite, 6,6-dimethyl-2-hepten-4-ynal (TBF-A), formed through three N-dealkylation pathways. We were the first to characterize them using in vitro studies with human liver microsomes and modeling approaches, yet knowledge of the individual enzymes catalyzing reactions remained unknown. Herein, we employed experimental and computational tools to assess terbinafine metabolism by specific cytochrome P450 isozymes. In vitro inhibitor phenotyping studies revealed six isozymes were involved in one or more N-dealkylation pathways. CYP2C19 and 3A4 contributed to all pathways, and so, we targeted them for steady-state analyses with recombinant isozymes. N-Dealkylation yielding TBF-A directly was catalyzed by CYP2C19 and 3A4 similarly. Nevertheless, CYP2C19 was more efficient than CYP3A4 at N-demethylation and other steps leading to TBF-A. Unlike microsomal reactions, N-denaphthylation was surprisingly efficient for CYP2C19 and 3A4, which was validated by controls. CYP2C19 was the most efficient among all reactions. Nonetheless, CYP3A4 was more selective at steps leading to TBF-A, making it more effective in terbinafine bioactivation based on metabolic split ratios for competing pathways. Model predictions did not extrapolate to quantitative kinetic constants, yet some results for CYP3A4 and CYP2C19 agreed qualitatively with preferred reaction steps and pathways. Clinical data on drug interactions support the CYP3A4 role in terbinafine metabolism, while CYP2C19 remains understudied. Taken together, knowledge of P450s responsible for terbinafine metabolism and TBF-A formation provides a foundation for investigating and mitigating the impact of P450 variations in toxic risks posed to patients.

Typical antimicrobials induce mast cell degranulation and anaphylactoid reactions via MRGPRX2 and its murine homologue MRGPRB2

Mast cells are unique immune cells that function as sentinels in host defence reactions, including immediate hypersensitivity responses and allergic responses. The mast cell-specific receptor named MAS-related G protein-coupled receptor X2 (MRGPRX2) triggers mast-cell degranulation, a key process in anaphylactoid reactions. It is widely observed that antimicrobials can induce pseudo-allergic reactions (i.e. IgE-independent mechanism) with symptoms ranging from skin inflammation to life-threatening systemic anaphylaxis. However, their direct involvement and the mechanisms underlying anaphylactoid reactions caused by antimicrobials have not been demonstrated. Structurally different antimicrobials were screened by Ca²⁺ imaging using MRGPRX2 overexpressing HEK293 cells. MRGPRX2 related anaphylactoid reactions induced by these components were investigated by body temperature drop and mast cell degranulation assays. We showed that MRGPRX2 is involved in allergic-like reactions to three types of antimicrobials in a dose-dependent manner. However, mast cells lacking the receptor show reduced degranulation. Furthermore, mice without MAS-related G protein-coupled receptor B2 (the orthologous gene of MRGPRX2) exhibited reduced substance-induced inflammation. Interestingly, β-lactam and antiviral nucleoside analogues did not induce anaphylactic reactions, which were also observed in vitro. These results should alarm many clinicians that such drugs might induce anaphylactoid reactions and provide guidance on safe dosage of these drugs.

Allergic Maculo-Papular Exanthema Due To Terbinafine

We report on a 76-year-old male patient who developed a maculopapular generalised exanthema due to terbinafine. Prick test was negative; patch test revealed a positive reaction after 48 h confirming the delayed-type allergic reaction. Non-pustular exanthema has only rarely been reported for terbinafine.