Stucco keratosis (SK) is a common, benign skin condition that primarily affects older adults. Dermatologists classify it as a specific, non-pigmented variant of seborrheic keratosis. The condition involves the excessive growth of keratinocytes, the main cell type in the outer layer of the skin.
Defining Stucco Keratosis
Stucco keratosis lesions are small papules, generally measuring between one and four millimeters in diameter. They often appear white, grey, or light tan, giving them a distinct “stuck-on” appearance, which is the origin of the name “stucco.”
The surface of the papules is rough and dry due to hyperkeratosis, which is the excessive production of keratin. A distinctive feature is that the lesions can often be gently scraped off without causing bleeding. They are most commonly found symmetrically on the distal extremities, particularly the lower legs, ankles, and feet.
SK is a condition of later life, with incidence increasing significantly after age 40 and peaking between ages 40 and 60. It is disproportionately observed in fair-skinned individuals and affects men up to four times more frequently than women. SK is entirely harmless and carries no risk of malignancy.
Underlying Contributing Factors
The cause of Stucco Keratosis remains largely unknown, but its development is strongly linked to established risk factors. The most significant factor is the natural process of skin aging, which slows skin cell turnover and leads to the accumulation of dead cells.
Chronic exposure to ultraviolet (UV) radiation is widely implicated as a contributing factor. Although many affected individuals report a history of sun exposure, the lesions frequently appear on areas of the lower legs not consistently exposed to sunlight. This suggests UV damage may act as a systemic trigger rather than a direct, localized cause.
Genetic predisposition also plays a role, as the condition sometimes shows a familial tendency and is genetically connected to common seborrheic keratoses. Mechanical factors, such as surface friction or the presence of dry skin, may also accelerate the formation of these papules.
Treatment and Management Options
Since SK is a benign condition, treatment is primarily for cosmetic reasons or if the lesions become physically irritated. For management of smaller lesions, topical treatments can be used. These include keratolytic agents, such as creams containing urea or salicylic acid, which soften and exfoliate the thickened keratin layer.
Topical retinoids, which regulate skin cell growth, may also be prescribed to help reduce the size and prominence of the papules. For definitive removal of individual lesions, dermatologists employ minor procedural techniques. These methods include cryotherapy, where liquid nitrogen is used to freeze and destroy the lesion; light electrocautery, which uses an electrical current to burn the tissue; and gentle curettage, where the lesion is carefully scraped away.
Physical removal techniques carry a risk of recurrence. Prevention involves consistent sun protection for the lower limbs and regular use of emollients to keep the skin hydrated and minimize friction.