Seborrheic Keratoses

Key Points
Congenital skin condition which typically develops on the scalp, face, or neck
Caused by defective cells in the ectoderm, thought to be genetic in nature
Initially consists of a single orange-yellow patch of skin, which may become warty or scaly in appearance at adolescence

Nevus sebaceous is a congenital skin condition which typically appears on the scalp, but may also develop on the face or neck. Present at birth, the condition initially consists of a single hairless patch of orange-yellow skin. During adolescence, the lesion may become warty, bumpy or scaly. In rare cases, the condition may be associated with neurological conditions such as epilepsy. Additionally, tumors may form within lesions, and may be either benign or malignant.

Nevus sebaceous is caused by groups of defective cells in the ectoderm, the part of the embryo which forms the outer layer of skin and associated tissues, and is thought to be due to a genetic abnormality. The condition may occur as a syndrome, in which multiple lesions are present in conjunction with various brain, skeletal or eye conditions, though it is exceedingly rare.

Differential Diagnosis (Other conditions with similar appearance)
Aplasia cutis congenita
Juvenile xanthogranulomas
Mastocytomas
Congenital triangular alopecia

Diagnosis
Key Points
Diagnosis based on characteristic appearance of lesions
Biopsy and other testing may be performed to confirm diagnosis and rule out other conditions

Nevus Sebaceous is typically diagnosed based on the characteristic appearance of lesions. Skin biopsy and other testing may be performed to rule out other similar appearing conditions or check for associated syndromes or disorders.

Treatment
Monitoring lesions for development of tumors is imperative
As long as nevi do not change, treatment is typically not required
Typical treatment consists of removal

Nevus sebaceous is typically not treated, as they do not generally cause issues in the affected person. However, monitoring for changes to lesions is imperative in early detection of the development of associated tumors. When treatment is required, it typically takes the form of removal, usually by surgical excision.