Hairy cell leukaemia diagnosed in a polysensitized patient with atypical haemorrhagic skin lesions

As the topical use of non-steroidal anti-inflammatory drugs (NSAIDs) has gained popularity recently, adverse reactions related to their application have also become more common. The authors present the case of a 49-year-old man, who used etofenamate gel to treat leg pain. Following sun exposure, haemorrhagic, atypical lesions appeared and after rapid spread of the symptoms, the patient was hospitalized. In the area of the etofenamate application as well as on both legs, arms, trunk and face, confluent, erythematous sero-papules and macules were found, along with petechiae on the oral mucosa. Splenomegaly and thrombocytopenia accompanied the skin symptoms, which prompted an oncohematological workup, and the patient was diagnosed with hairy cell leukaemia. Epicutaneous testing (ET) was performed and found a positive reaction to etofenamate gel as well wood tar, propylen glycol, fragrance mix I, methylisothiazolinone, benzoic acid and balsam of Peru. The lymphocyte transformation test (LTT) and CD69 expression were negative for etofenamate. Orv Hetil. 2020; 161(38): 1646-1651.