125 - Keratosis pilaris and variants

Abstract

Keratosis pilaris (KP) is a common inherited disorder of unknown etiology characterized by keratin plugging of follicular orifices affecting characteristic body sites, typically the extensor aspects of the upper arms, anterior surfaces of the thighs, and lateral aspects of the cheeks. Perifollicular erythema is common, and a background of erythema on the cheeks may also be seen in KP rubra. Other variants of KP include erythromelanosis follicularis faciei et colli and keratosis pilaris atrophicans, which includes keratosis pilaris atrophicans faciei (ulerythema ophryogenes), keratosis follicularis spinulosa decalvans, folliculitis spinulosa decalvans, and atrophoderma vermiculatum. KP may be seen in conjunction with other skin disorders, such as atopic dermatitis; it may also arise in states of androgen and insulin dysregulation or in infants with malnutrition. Extensive disease has also been observed in patients with Down syndrome and in the setting of certain medications. Initial treatments aim to decrease excessive skin roughness and follicular accentuation. Keratolytic agents such as glycolic acid, ammonium lactate, salicylic acid, and urea-containing humectants are the mainstays of treatment. Twice-daily application of one of these agents for at least a 3-week trial is recommended. Once adequate relief of symptoms has been achieved, maintenance therapy of weekly or twice-weekly application of a topical keratolytic agent is recommended. Topical retinoids may be utilized in some cases. Oral isotretinoin has been helpful in some patients with ulerythema ophryogenes, atrophoderma vermiculatum, and keratosis follicularis spinulosa decalvans. If a significant inflammatory component is present, the inflammation can be treated for defined short-term periods with a medium-potency topical corticosteroid in an emollient base. Light therapies have been utilized for several variants of KP.