Flagellate Dermatosis in a Child

An 8-year-old boy diagnosed with Hodgkin's lymphoma stage 3b was started on an ABVD (adriamycin, bleomycin, vinblastine and dacarbazine) chemotherapy regimen and achieved remission post-second cycle. After four cycles of chemotherapy, the child developed an itchy rash over the trunk and shoulders [Figure 1]. There was no history of fever, trauma, insect bite, muscle pains, joint swellings, skin sclerosis, Raynaud's phenomenon or intake of shiitake mushrooms. There was no past history of skin disease in the child. Examination showed maculopapular reddish to brown streaky hyperpigmentation over the shoulders and trunk. The rest of the examination was normal. Investigations revealed a normal complete blood count with normal eosinophil count, kidney function and liver function tests, erythrocyte sedimentation rate and C-reactive protein.Figure 1: Erythematous to brown streaky hyperpigmentation on the shoulders and trunkWhat is the diagnosis? Answer The differentials for flagellate hyperpigmentation include mechanical flagellation in a religious or sexual context, contact dermatitis due to poison ivy, intake of shitake mushrooms, jellyfish stings, Paederus insect bites, chikungunya fever, hypereosinophilic syndromes, dermatomyositis, systemic sclerosis, systemic onset juvenile idiopathic arthritis and chemotherapy-induced flagellate hyperpigmentation (bleomycin, docetaxel, bendamustine).[1] In this case, based on history and examination and the available investigations, the diagnosis of bleomycin-induced flagellate hyperpigmentation (cumulative dose of 60 U) was made. Parents were counselled, child received oral antihistaminics and completed six cycles of chemotherapy. Two months later the pigmentation had markedly reduced. Discussion Bleomycin, an antineoplastic drug, is known to have increased skin toxicity due to relative absence of skin hydrolase resulting in its delayed clearance from the skin.[2] Flagellate hyperpigmentation is a unique cutaneous side-effect of bleomycin reported in 8–20% of patients.[3] It usually presents as a prodrome of pruritis followed by erythematous linear hyperpigmentation on the trunk and/or shoulders which gradually deepens to brown streaks. The development of flagellate erythema is dose-independent and may precipitate at cumulative doses as low as 15 Units and anytime from 1 day to 9 weeks after bleomycin administration.[3,4] Hypothesized pathogenic mechanisms include local increase in melanogenesis, direct toxic effects of bleomycin, localized drug eruption secondary to its leakage from blood vessels after scratching and alterations of normal pigmentation patterns.[1] Histopathologically, the lesions may show an urticarial hypersensitivity reaction, localized increase in melanogenesis, inflammatory oncotaxis and lymphocytic vasculitis.[4] The treatment involves the use of antihistamines, topical or oral corticosteroids, administration of bleomycin as a continuous infusion or withdrawal of the offending drug in case of severe reaction.[5] Learning points Bleomycin-induced flagellate hyperpigmentation is a unique cutaneous side effect of bleomycin reported in 8–20% of patients. Diagnosis is primarily clinical with characteristic flagellate appearance of the lesions in the context of a patient receiving bleomycin There is no observed dose–effect relation for this adverse reaction Management is supportive (with antihistaminics and topical or oral steroids) and rarely requires withdrawal of bleomycin In most cases, complete resolution is documented over a period of few months after the stoppage of bleomycin. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.