[Bullous mastocytosis in infancy: a rare presentation]

Mastocytosis is a rare condition related to an abnormal proliferation of mast cells and their accumulation in tissues. Cutaneous mastocytosis is the most common form and mainly affects newborns and infants. The symptoms are caused by the release of mediators contained in mast cells, including histamine. Mastocytosis may be associated with a mutation in the gene encoding the c-kit receptor. Clinically, there are different dermatological findings, which combine acute cutaneous, digestive, or even hemodynamic manifestations in varying degrees. The diagnosis is confirmed by the histological study of a skin sample. We report here the case of a 4-month-old infant suffering from diffuse cutaneous bullous mastocytosis, a very rare variety of mastocytosis. This infant had an erosive and bullous manifestation of dermatosis, initially confused with impetigo. The proliferation of bullous lesions led to her hospitalization. Codeine intake for pain was responsible for a large and extensive bullous reaction associated with anaphylactic shock. This context of bullous spread occurring after taking codeine led to the suspicion of bullous diffuse cutaneous mastocytosis, a diagnosis that was confirmed histologically. This observation demonstrates the difficulty of mastocytosis diagnosis, mostly due to its rarity, especially in its diffuse bullous forms. The rapid deterioration of this patient, after the codeine prescription, emphasizes the importance of the eviction of histamine-releaser compounds in the management of this disease.