Lesions are numerous and symmetrically localized on sun-exposed areas of the skin, particularly the extensor surfaces of the forearms and shins. Face, neck, upper chest, shoulders, and dorsal surfaces of the feet are less commonly involved. The primary lesion is a small keratotic papule that flattens, increases in size, and transforms into a pinkish-brown patch measuring 5-10 mm in diameter that is flat or slightly atrophic. Under magnification, most lesions have a very thin, dark cornoid lamella bordering the patch. A slight roughness may be felt on palpation.

The diagnosis is based on the characteristic clinical presentation and histopathological findings.

• Porokeratosis of Mibelli , which occurs in childhood and forms a single plaque with irregular borders, up to 10 cm in diameter, often on the dorsal surface of the hands. Less frequently, a linear (zosteriform) distribution of lesions is observed, mainly located on the extensor surfaces of the limbs, hands, and feet. The morphological features of porokeratosis of Mibelli are identical to actinic porokeratosis.
• Disseminated superficial porokeratosis (non-actinic)
• Actinic keratosis
• Granuloma annulare
• Lichen planus
• Stucco keratosis(keratosis alba)
• Tinea corporis
• Flat warts

There are no effective treatments. The following treatment methods have been used with varying degrees of success:

Local treatment:

• High-potency corticosteroids applied twice daily for several weeks.
• 5-fluorouracil cream.
• Keratolytics (urea, salicylic acid).
• Topical retinoids
• Imiquimod 5% cream.

Systemic treatment:

• Isotretinoin 20 mg/day in combination with local treatment.
• Cryotherapy
• Phototherapy.