mastocytoma; juvenile xanthogranuloma; pilomatricoma

Common Lumps and Bumps in Children - What it is

Mastocytoma is an uncommon skin lump caused by an excess of a type of white blood cell found in the skin known as mast cells.

They present as a single or multiple yellow-tan lump often on the arms, neck or trunk. It may be itchy or have no symptoms at all.

The surface of the lump often has a wrinkled "orange-peel" like appearance and may uncommonly blister. Rubbing the lump may cause it to turn red and swell up, resembling an insect bite.

JUVENILE XANTHOGRANULOMA (JXG):

Juvenile xanthogranuloma (JXG) is an uncommon skin lump occurring mainly in infants and young children.

It is caused by an excess of a type of cell found in the skin known as histiocytes and is benign.

JXG presents as a firm, round lump in the skin with an orange to yellow colour. They may initially appear reddish.

These usually occur in the head, neck or upper body region as a single lump but sometimes some patients may have multiple JXG.

JXG are usually not itchy or painful.

Rarely, JXG may be found outside the skin in other areas including the eyes, muscles or liver.

Patients with many JXG may rarely have an increased risk of a type of childhood leukaemia and may need to be regularly monitored.

PILOMATRICOMA:

A pilomatricoma is a benign growth arising from cells forming the hair follicle.

It presents as a firm-to-hard, flesh-coloured or bluish lump, usually on the head, neck or upper limbs.

A pilomatricoma usually does not cause any symptoms but it may become red and painful if it becomes inflamed or infected. It may be painful on direct pressure.