Keratosis Pilaris (KP) in mild cases is limited to the posterior upper arms and manifests as a “horny plug” in each hair follicle. It is due to abnormalities in keratinization in the upper lining of the hair follicle that collects, causing a horny plug. This gives it a very uniform distribution as shown in the photographs above and below. The thighs are the next most common site of involvement and in more severe cases the follicular plugs may extend down the arms and legs.
It may progress further to involve the back, chest, face, trunk and buttocks. Facial and arm involvement is frequently mistaken as acne. It is Autosomal Dominantly inherited with variable penetrance. It is estimated that up to half of all children have KP and it may be associated with other disorders such as ichthyosis vulgaris (see below). It is most prominent during the teen years, least common in the elderly but may be seen at any age.
The individual lesions are small, acuminate (tapers to a slender point), follicular papules that may or may not be erythematous. Occasionally inflammatory acneiform pustules and papules may appear. Conditions associated with KP include:
- Ichthyosis follicularis
- Atrichia with papular lesions
- Mucoepidermmal dysplasia
- Cadiofaciocutaneous syndrome
- Ectodermal dysplasia with corkscrew hairs
- KID Syndrome (Keratosis-Ichthyosis-Deafness)
TREATMENT: Patients with KP are susceptible to developing eczema. Please refer to my blog on Eczema to get the low down on how to prevent this by clicking HERE. It is important to avoid hot water exposure and to avoid picking or scrubbing the areas. Treatment is difficult but some patients do well with keratolytics such as Ammonnium Lactate 12% as well as Salicylic Acid preparations. Some patients have responded to topical Retinoids and Calcipotriene. Pulsed dye lasers have been used for erythematous variants. To read more about KP click HERE and HERE.