Cutaneous mastocytosis-Conglomerate of diagnostic tools: A report of four cases.

Mast cells are naturally distributed in the dermis, respiratory, gastrointestinal/genitourinary mucosa, adjacent to blood vessels, lymphatics, and peripheral nerves. The most common site for the abnormal accumulation of mast cells is the skin, which is known as cutaneous mastocytosis. We report four cases of cutaneous mastocytosis with erythematous maculopapular to bullous lesion along with a positive Darier sign. Skin biopsy, with special stains like Toluidine blue, Giemsa stain, immunohistochemistry (IHC) for CD117, and serum tryptase level correlations were done. Mastocytosis can affect only the cutaneous sites or involve multiple organs. It is most common in infancy with varied clinical presentations, thus requiring a high index of suspicion with histopathological correlation. Although the prognosis is good, there remains a risk of sudden mast cell degranulation due to triggering agents and subsequent collapse.