Flagellate erythema or flagellate dermatitis is characterized by pruritic linear streaks of erythematous or brown patches and plaques, presenting with a whip-like appearance. The lesions are associated with various etiologies like consumption of shiitake mushrooms, rheumatologic disorders, and drugs, among others. Its association with bleomycin as an adverse reaction was first reported in 1970. It is a rare phenomenon with a reported incidence of only 8 to 20%.

This is a case of a 29-year-old male with mediastinal seminoma who was started on bleomycin, etoposide, and cisplatin (BEP) regimen. He developed pruritic erythematous papules and linear streaks of erythematous and brown patches and plaques, most prominent on the trunk and extremities ten days after starting the chemotherapy regimen cycle. The initial presentation was subtle, with worsening after continued administration of bleomycin. A skin punch biopsy showed spongiotic interface dermatitis with eosinophils, and the patient was managed symptomatically.

Flagellate erythema is a rare form of cutaneous reaction to bleomycin. It may have a subtle presentation initially but it must be suspected in patients on bleomycin presenting with sudden onset linear or whip-like erythematous or brown lesions.