Keratosis Follicularis

Key Points
Also known as keratosis follicularis
Manifests as greasy appearing brown bumps which usually appear around puberty
Lesions often begin on the face, scalp, chest, or back

Darier’s disease is a fairly unusual skin disease that runs in families. The rash usually begins around the teenage years, or later, and is characterized by the development of dark crusty (dirty appearing) bumps (papules). The rash most often develops on the chest, neck, back, ears, forehead, or groin. The rash can also lead to fragile fingernails, and it can often cause a bad odor. Occasionally a keratoderma can form, in which the skin on the palms and soles thickens dramatically. The eruption is often aggravated by sunlight and heat so it is often worse during the summer months. Darier disease is not contagious, rather the result of a genetic mutation in skin cells.

Differential Diagnosis (Other conditions with similar appearance)
Acrokeratosis verruciformis of Hopf
Familial Benign Pemphigus (Hailey-Hailey disease)
Seborrheic Dermatitis
Transient Acantholytic Dermatosis

Diagnosis
Key Points
dark crusty “dirty appearing” bumps, usually across the scalp, chest, or back
skin biopsy if helpful
often a family history

Gene sequencing or a skin biopsy can confirm diagnosis, which is usually first detected by visual inspection and a family history.

Treatment
Moisturizers, topical steroids, and topical retinoids can be helpful; keratolytics are also useful
Sunscreens along with loose clothing and avoiding hot, humid environments
*Oral treatment options include antibiotics, systemic retinoids such as Acitretin, and there have been reports of occasional improvement with oral contraceptive agents in women who flare during menstrual cycles

There is no cure for Darier’s disease. When symptoms are mild, treatment is limited to good moisturizers and sunscreen, along with an antibiotic soap, which will also help with the odor. Applying petroleum jelly twice a day will help to heal the lesions. Oral retionoids (Acitretin or Isotretinoin) are administered for more severe cases, and oral antibiotics are taken during flare-ups.