What Is Keratosis Follicularis?

Keratosis follicularis is a type of skin disorder that causes people to develop rough bumps and thick plaques or skin lesions. The condition is also known as Darier disease and affects roughly 1 in 36,000 to 100,000 people.

The condition typically develops at puberty and during the teen years. However, it can also come on in childhood and early adulthood. It is incredibly rare for keratosis follicularis to develop after ages 30–40.

This article discusses the symptoms, causes, and treatment options for people with keratosis follicularis.

Keratosis Follicularis Symptoms

The initial symptoms of keratosis follicularis are small, firm, and greasy bumps on the skin. These bumps can be the same color as the skin or brown or yellow.

Typically, the lesions form around sebaceous glands, which are glands in the body that release an oily substance known as sebum to lubricate the skin and hair. The areas most affected are the chest, back, forehead, and scalp. However, skin creases such as the groin area can also be affected.

Other symptoms that occur in keratosis follicularis include:

• Brown, greasy crust on the lesions
• Thick and wartlike lesions
• Scaly and darkened areas of skin
• Odor coming from the lesions
• Itchy skin
• Blisters
• Raw and painful skin
• Small yellow-brown, wartlike bumps on the backs of the hands or feet
• Horny bumps, known as punctate keratoses, on the palms and soles of the feet
• Pits in the palms or soles of the feet
• Small bumps in the mouth, throat, or esophagus
• Overgrowth of the gums
• Lesions in the anus or rectum

Once the lesions begin to form, they grow slowly over time until they connect into a larger wartlike plaque that covers significantly more skin. In some cases, the lesions become infected and cause a more severe threat to a person’s overall health.

Causes

Keratosis follicularis is genetic and occurs because specific genes mutate. Genes provide your cells with the instructions they need to create proteins that help with the body's overall function. When a change occurs to a specific gene, it compromises those instructions.

The gene most associated with the disease is the ATP2A2 gene, which is responsible for providing instructions to create a specific type of enzyme known as sarco-/endoplasmic reticulum calcium-ATPase2 (SERCA2). This enzyme is tasked with the control of how many positively charged calcium atoms make their way into cells.

Diagnosis

A physical exam of the affected area is needed to diagnose keratosis follicularis. A healthcare provider will discuss your health history and any other symptoms you are experiencing as part of the investigation process.

Blood tests look for indicators of disease, and an oral examination checks for lesions within the throat or mouth. Finally, a skin biopsy (removing a sample of skin for analysis in a lab) is often done to get a closer look at the cells of the lesions.

Treatment

Treating keratosis follicularis depends heavily on the severity of the disease. For some, simple changes such as wearing more sunscreen and loose-fitting clothing can help. Moisturizing the affected area and staying out of the heat can also prevent or reduce symptoms.

Other treatments may be required if the condition is severe or a person cannot cope with the symptoms. Some treatment options include:

• Retinoids: Topical retinoids are a synthetic version of vitamin A. They are applied directly to the skin as a cream or emollient.
• Corticosteroids: Topical corticosteroids reduce inflammation. They can be applied directly to the skin as a cream or ointment.
• Oral Retinoids: In more severe cases of the disease, a person may opt for taking retinoids by mouth.

Coping

Having keratosis follicularis can be difficult if it is severe. However, for those with mild disease, coping with the symptoms can be as easy as making a few lifestyle changes, such as staying out of the sun and heat and wearing loose-fitting clothing.

Since there is no cure for the disorder, getting effective treatment is crucial to keeping flare-ups to a minimum.

Summary

Keratosis follicularis, also known as Darier disease, is a genetic skin disorder that affects roughly 1 in 35,000 to 100,000 people. It typically begins when a person enters puberty or their teen years and starts with small bumps on the palms or soles of the feet and small lesions on an affected skin area.

The lesions can grow into one large patch of rough, wartlike skin, covering a much larger body area. Some people may experience symptoms unrelated to the lesions, such as seizures or learning disabilities.

A healthcare provider must rule out other skin diseases to diagnose and treat the condition. They do this by collecting a health and family health history, physical examination, and skin biopsy. Once it is determined that you have keratosis follicularis, you will be provided with treatment options, including corticosteroids or oral or topical retinoids. 

A Word From Verywell

Having a skin disorder can be challenging to deal with, especially if it is severe. Keratosis follicularis, although incurable, isn’t always severe and can often be managed effectively through lifestyle changes and medications.

The best thing you can do is to speak to your healthcare provider about your options. They will help you manage flare-ups and give you the best possible treatment options for your individual case.