Linear Porokeratosis

Key Points
Uncommon skin condition typically affecting the limbs, head/neck, or torso
Exact cause is unknown, but some cases may be genetic in nature
Consists of round lesions with a ridged border which form in linear patterns

Linear porokeratosis is an uncommon skin condition which typically affects the limbs, head/neck, or torso. The condition consists of the formation of round lesions which have a characteristic ridged border. Lesions form in a linear pattern, typically along the path of sensory nerves. Lesions may form on a limb, or on one side of the torso or head/neck. Lesions are typically asymptomatic. In some cases, certain skin cancers may form within lesions.

The cause of linear porokeratosis is unknown, but it is thought that in some cases the condition may be genetic in nature. In these cases, affected persons often show a family history of various forms of porokeratosis.

Differential Diagnosis (Other conditions with similar appearance)
Linear verrucous epidermal nevus
Psoriasis, Plaque

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

Diagnosis of Linear porokeratosis is typically based on the characteristic appearance of the affected area. Skin biopsy may be performed to confirm the diagnosis and to rule out other, similar appearing conditions.

Treatment
No cure for the condition
Goal of treatment is to reduce symptoms
Sun protection is recommended to reduce risk of developing associated cancerous conditions

There is no cure for linear porokeratosis. The goal of treatment is to reduce symptoms, primarily the appearance of lesions. In cases due to a drug reaction, ceasing the medication will resolve symptoms. In other cases, medications which may be prescribed include 5-fluorouracil or calcipotriol creams, oral acitretin or Isotretinoin, cryotherapy, dermabrasion, and carbon dioxide laser therapy. It is recommended that affected persons practice appropriate sun protection, as this may reduce the risk of developing associated cancerous conditions.