Disseminated superficial actinic porokeratosis

A skin condition characterized by multiple, small, annular lesions

Disseminated superficial actinic porokeratosis (DSAP) is a chronic skin condition that is characterized by the presence of multiple, small, annular lesions with a distinctive ridge-like border. These lesions are primarily found on sun-exposed areas of the skin, such as the arms and legs. DSAP is considered a type of porokeratosis, a group of disorders that involve abnormal keratinization of the skin.

Pathophysiology

DSAP is believed to result from a combination of genetic predisposition and environmental factors, particularly ultraviolet (UV) radiation from sun exposure. The condition is associated with mutations in the MVK gene, which plays a role in the mevalonate pathway, crucial for cholesterol synthesis and other cellular functions. The lesions of DSAP are characterized by a cornoid lamella, a column of parakeratotic cells, which is a hallmark of porokeratosis.

Clinical Presentation

Patients with DSAP typically present with multiple, small, reddish-brown papules or plaques that have a well-defined, raised border. These lesions are often annular or ring-shaped and can coalesce to form larger patches. The lesions are usually asymptomatic but may occasionally cause mild itching or irritation.

Diagnosis

The diagnosis of DSAP is primarily clinical, based on the characteristic appearance of the lesions and their distribution on sun-exposed areas. A skin biopsy can be performed to confirm the diagnosis, revealing the presence of a cornoid lamella and other histological features typical of porokeratosis.

Management

Management of DSAP focuses on minimizing sun exposure and protecting the skin from UV radiation. Patients are advised to use broad-spectrum sunscreen, wear protective clothing, and avoid peak sun hours. Topical treatments, such as 5-fluorouracil cream or imiquimod, may be used to reduce the appearance of lesions. In some cases, laser therapy or cryotherapy may be considered.

Prognosis

DSAP is a chronic condition that tends to persist throughout a patient's life. While the lesions are generally benign, there is a small risk of malignant transformation to squamous cell carcinoma. Regular monitoring and skin examinations are recommended to detect any changes in the lesions.

Related pages

• Porokeratosis
• Actinic keratosis
• Squamous cell carcinoma