Allopurinol induced generalized eosinophilic pustular folliculitis

A Case of Eosinophilic Pustular Folliculitis since Birth

A newborn male infant presented with multiple pustules and erosions with erythema involving his scalp and forehead at birth. One week after birth, new pustules continued to appear, forming crusted, ring-shaped plaques with pigmentation. Tests for possible pathogens were negative. Tzanck smear and skin biopsy revealed pustules beneath the stratum corneum at sites corresponding to hair follicles, which contained eosinophils and neutrophils. Taken together, a diagnosis of eosinophilic pustular folliculitis (EPF) was made. The pustules on the head disappeared rapidly with topical corticosteroid treatment, although new eruptions were still observed on the trunk about one month after birth. To our knowledge, only two cases of EPF since birth have been reported to date. Here, we also discuss the differential diagnosis of noninfectious pustular diseases at birth, including erythema toxicum neonatorum and transient neonatal pustular melanosis. These diseases, and EPF, may present with very similar clinical symptoms at birth, and the Tzanck test or biopsy may be required for differential diagnosis.

A Case of Ofuji Disease Successfully Treated with the Combination of Low-Dose Indomethacin and Topical Tacrolimus

Eosinophilic pustular folliculitis (EPF) (Ofuji disease) is a chronic, noninfectious pruritic cutaneous disorder of unknown etiology. No official guidelines are available for its treatment. Herein we present the case of a 59-year-old Caucasian man admitted to our outpatient clinic due to a generalized itchy skin rash characterized by papulo-pustules involving the face, trunk, and limbs. Histological examination supported the clinical diagnosis of EPF (Ofuji disease). The combination of low-dose oral indomethacin and topical tacrolimus ointment once a day led to a complete resolution of the lesions as well as associated symptoms in 8 weeks.

Facial pustules due to drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms may histopathologically mimic eosinophilic pustular folliculitis: A case report

Pustules with facial and/or neck edema is one characteristic feature of drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms (DIHS/DRESS) at the early stage. Although several retrospective histopathologic studies on DIHS/DRESS have been reported, the detailed histopathologic findings of facial pustules for DIHS/DRESS are unavailable. We herein report a case of DIHS/DRESS with facial pustules that was histopathologically similar to eosinophilic pustular folliculitis (EPF). Eosinophilic infiltration into expanded follicles and sebaceous glands, which is highly characteristic of EPF, was detected in pustules due to DIHS/DRESS in this case. There are numerous pathophysiological similarities between DIHS/DRESS and EPF, which may cause their histopathologic similarity. Our findings suggest that facial pustules of DIHS/DRESS may histopathologically mimic EPF.

Eosinophilic Drug Allergy

While peripheral or tissue eosinophilia may certainly characterize drug eruptions, this feature is hardly pathognomonic for a medication-induced etiology. While delayed drug hypersensitivity reactions with prominent eosinophilic recruitment have been typically classified as type IVb reactions, their pathophysiology is now known to be more complex. Eosinophilic drug reactions have a diversity of presentations and may be benign and self-limited to severe and life-threatening. The extent of clinical involvement is also heterogeneous, ranging from isolated peripheral eosinophilia or single organ involvement (most often the skin and lung) to systemic disease affecting multiple organs, classically exemplified by drug-reaction with eosinophilia and systemic symptoms (DRESS). The spectrum of implicated medications in the causation of DRESS is ever expanding, and multiple factors including drug metabolites, specific HLA alleles, herpes viruses, and immune system activation have been implicated in pathogenesis. Due to this complex interplay of various factors, diagnostic workup in terms of skin and laboratory testing has not been validated. Similarly, the lack of controlled trials limits treatment options. This review also describes other localized as well as systemic manifestations of eosinophilic disease induced by various medication classes, including their individual pathophysiology, diagnosis, and management. Given the multitude of clinical patterns associated with eosinophilic drug allergy, the diagnosis can be challenging. Considerable deficits in our knowledge of these presentations remain, but the potential for severe reactions should be borne in mind in order to facilitate diagnosis and institute appropriate management.

Drug-induced skin reactions: a pathologist viewpoint

Cutaneous drug reactions are common adverse effects that occur in about 2-3% of the hospitalized patients. They have both immunologic and non-immunologic underlying mechanisms. These reactions are clinically and histologically similar to dermatoses. Their significant clinical indicators include: history of drug intake, atypical clinical features and improvement after cessation of the offending drugs. Their diagnostic histological clues include the presence of mixed histological patterns, apoptotic keratinocytes, eosinophils (dermis and epidermis), papillary dermal edema and extravasations of erythrocytes. However, no single clinical or histological feature is specific of drug eruptions. This work attempts to classify the histomorphologic reactions to various drugs in defined categories for assistance in morphologic diagnosis.

Allopurinol in dermatology

Off-label use is common in dermatology, and is inevitable for rare cutaneous diseases such as perforating dermatosis. Allopurinol is traditionally considered to be a drug for hyperuricemia only, but the recent demonstration of its efficacy in congestive heart failure has spurred renewed interest in its application in other clinical specialties. In dermatology, allopurinol is best known for its severe cutaneous adverse reactions. Recent genomic studies conducted in Taiwan have discovered useful HLA markers for determining the susceptibility of Stevens-Johnson syndrome and toxic epidermal necrolysis associated with allopurinol. Allopurinol has also been used in a number of dermatologic disorders including acquired reactive perforating collagenosis, sarcoidosis, psoriasis and granulomas caused by methacrylate microspheres, silicon and tattoos. Allopurinol may express its therapeutic effects via its antioxidation or anti-inflammatory properties, or its ability to improve vascular function.