DermNet NZ

Facts about the skin from DermNet New Zealand Trust. Topic index: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z


What is mastocytoma?

Mastocytoma is the name given to a localised form of cutaneous mastocytosis. Cutaneous mastocytosis occurs when there are too many mast cells in the skin.

What do they look like?

Mastocytoma usually appears in early childhood at a few months of age. One or more red, pink or yellow lumps, which may vary in size from about one to 5 centimetres in diameter and can appear anywhere on the skin. Rubbing causes mastocytomas to redden and swell for 15 minutes or so. Often there are no symptoms but they may be itchy and sometimes they may blister, especially when rubbed. Occasionally flushing may occur when the mast cells release chemicals such as histamine into the skin.

Mastocytoma mastocytoma
The same lesion after rubbing

If the mastocytoma is causing a lot of itching, this can often be relieved with oral antihistamines. No other treatment is necessary as mastocytomas usually disappear as the child grows older.

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Author: Vanessa Ngan, staff writer

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