Porokeratosis (linear, Mibelli, plantar) - Skin in Adult
Linear porokeratosis is an uncommon variant that presents in infancy or early childhood as unilateral lesions contained within the lines of Blaschko. A less-common generalized form affects multiple extremities as well as the trunk. The linear variant of porokeratosis has the highest potential of malignant transformation of all porokeratoses, with squamous cell carcinoma being the most frequently associated malignancy.
Porokeratosis of Mibelli
The classic porokeratosis of Mibelli presents during infancy or early adulthood as an asymptomatic to slightly pruritic, brown to skin-colored, annular plaque with a peripheral hyperkeratotic, ridge-like scale. Lesions can range in size from 1 to 2 mm up to several centimeters in diameter. Larger lesions tend to form on the lower leg and foot, although giant facial and genital lesions have been described. The condition may be inherited as an autosomal dominant trait. Antecedent trauma or immunosuppression may be present. Lesions often persist indefinitely.
Porokeratosis Palmaris et Plantaris Disseminata (Plantar Porokeratosis)
Porokeratosis palmaris et plantaris disseminata is an autosomal dominant inherited genodermatosis presenting in adolescence or young adulthood. Initial lesions first appear on the palms and soles as small, uniform hyperkeratotic lesions with characteristic leading ridge with a longitudinal furrow. Subsequent lesions spread to involve other areas of the body, including non-sun-exposed sites as well as the mucous membranes. Males are affected twice as often as females.
Q82.8 – Other specified congenital malformations of skin
400080004 – Porokeratosis
- Tinea corporis – KOH prep will demonstrate branching or curving fungal hyphae crossing cell borders.
- Granuloma annulare
- Viral warts (especially flat warts)
- Actinic keratosis – Scale present throughout the lesion.
- Lichen planus