Mastocytoma, Solitary

Key Points
Localized form of mastocytosis which may appear anywhere on the skin
Exact cause is unknown
Consists of the formation of one or more yellow, pink or red lumps which may be up to 5cm in size, and may be accompanied by itching or blistering

Mastocytoma is a localized form of mastocytosis. Lesions consist of one or more yellow, pink or red lumps which may appear anywhere on the skin. Lesions may be accompanied by itching or blistering, and will swell and redden if rubbed. Flushing may also occur due to the nature of the condition, and the cells responsible release chemicals into the skin.

Mastocytoma's cause is unknown, and it typically appears in infancy or early childhood. The condition results from an excess of mast cells in the skin, which causes an increased release of certain chemicals, including histamines.

Differential Diagnosis (Other conditions with similar appearance)
Amyloidosis, Macular
Lentigo
Amyloidosis, Nodular Localized Cutaneous
Linear IgA dermatosis
Carcinoid
Lymphocytoma cutis
Epidermolysis bullosa
Pseudolymphoma, Cutaneous
Herpes simplex

Diagnosis
Key Points
Diagnosis based on the characteristic appearance of the affected area
Skin biopsy may be performed to confirm diagnosis and rule out other conditions

Mastocytoma is typically diagnosed based on the characteristic appearance of the affected area. A skin biopsy may be performed to confirm the diagnosis and to rule out similar appearing conditions.

Treatment
Condition is typically self-resolving, making curative treatment unnecessary
*Certain medications may relieve symptoms

Mastocytoma tends to spontaneously resolve with age, making curative treatment unnecessary. Oral antihistamines may be administered to relieve symptoms such as itching.