Miliaria crystallina induced by idarubicin and all-trans-retinoic acid: Two case reports.

Miliaria crystallina is a benign, self-limiting disorder of the eccrine sweat glands characterized by the obstruction of the sweat ducts, which leads to secondary sweat retention into stratum corneum. We present two patients with MC during treatment with idarubicin and all-trans-retinoic acid (ATRA) for acute promyelocytic leukaemia (APL). Anthracyclines can be excreted through sweat and induce MC through exfoliation. The use of idarubicin in combination with ATRA would favour the process of producing a peeling effect. Reports of MC associated with idarubicin and ATRA are scarce. Recognizing this benign entity and its triggers will help to differentiate it from other skin reactions, improving the management of patients by avoiding unnecessary studies and treatments.