Atypical Cutaneous Blastomycosis in a Child With Juvenile Idiopathic Arthritis on Infliximab

Abstract

Blastomyces dermatitidis is a dimorphic fungus endemic to much of North America, particularly the soils of the midwestern and southeastern United States. Human infection typically occurs through inhalation of airborne conidia, which can be followed occasionally by dissemination to the skin, bone, genitourinary system, and central nervous system. A hallmark of the pathogen is that it can cause disease in both immunocompetent and immunosuppressed populations. Blastomycosis is rare in pediatric patients, with cutaneous manifestations occurring even less frequently. Here, we report the case of a 9-year-old boy on iatrogenic immunosuppression with infliximab and methotrexate for juvenile idiopathic arthritis who presented with a nonhealing, indurated plaque of his right ear with significant superficial yellow crusting in the absence of constitutional symptoms. After failing a prolonged course of topical and oral antibiotic therapy, biopsy and tissue culture revealed Blastomyces dermatitidis infection. The area cleared after treatment with oral fluconazole and withdrawal of infliximab. To our knowledge, this is the first report of a pediatric patient developing an infection with B dermatitidis after initiation of therapy with a tumor necrosis factor-a inhibitor. This case also highlights an unusual morphology of cutaneous blastomycosis in an iatrogenically immunosuppressed child.

Invasive fungal infections in pediatric patients treated with tumor necrosis alpha (TNF‐α) inhibitors

“…Table shows the pediatric patients with IFIs that were identified through the literature review and were provided with the required information . Not surprisingly, most of these children were treated with IFX and the vast majority of these cases come from the US.…”

“…In a review of the incidence of specific OIs among children with JIA, Coccidioides infection had an incidence rate at 0.021/100 patient- Table 2 shows the pediatric patients with IFIs that were identified through the literature review and were provided with the required information. [74][75][76][77][78][79][80][81][82][83][84][85][86][87][88][89] Not surprisingly, most of these children were treated with IFX and the vast majority of these cases come from the US. Concomitant treatment with other immunosuppressive agents seems to play a crucial role as well.…”

Enlarging verrucous plaques in a teenager

“…Studies have shown that pediatric infections account for 3%‐11% of all blastomycosis cases . Cases describing primary cutaneous blastomycosis in children are limited to immunosuppressed patients . The patient in this case was previously healthy and denied systemic symptoms throughout the history of the lesions.…”

Clinical Manifestations and Treatment of Blastomycosis

“…31 Clinical data on blastomycosis in the setting of TNF- α exposure is sparse and is limited to case reports. 20,59 Nevertheless, blastomycosis was listed in the 2008 warning issued by the Food and Drug Administration regarding increased risk of fulminant infections with endemic mycosis in patients receiving TNF inhibitor therapy. 20 …”