What is folliculitis decalvans?

It’s normal to lose several strands of hair per day. However, noticeably thinning hair, baldness, and skin irritation may warrant an investigation.

Hair loss (alopecia) is a relatively common condition, according to the American Academy of Dermatology. Short-term conditions, such as pregnancy, may cause temporary hair loss. But long-term hair loss that leads to bald patches likely stems from an underlying medical condition. Folliculitis decalvans (FD) is one of the possibilities.

FD stems from widespread inflammation within the hair follicles. This causes the follicles to lose hairs and stop producing new ones. It can also lead to other inflammatory symptoms.

Learn more about FD and how you can manage this condition. While there’s no cure, treatment can prevent further balding, sores, and scarring.

Inflammation in the hair follicles eventually leads to a variety of noticeable symptoms. The first symptom of FD is itchiness. This is related to the underlying inflammation that affects the hair follicles. Unlike traditional hair loss in which you might only experience bald spots, FD also includes inflammatory symptoms.

Over time, you may notice the following signs on balding areas of skin:

  • redness
  • swelling
  • pustules (blister-like pimples that contain pus)
  • scars

Hair loss from this condition often occurs in oval or round patches.

Alopecia is perhaps most noticeable on the scalp because that’s the area of the body with the most hair. However, hair loss can occur anywhere you have hair on your body. To that end, FD can develop on these same areas. In addition to the scalp, you might have symptoms of this condition on your:

  • arms
  • face (more common in men)
  • chest
  • legs
  • pubic region

FD is a cross between alopecia and folliculitis, the latter term used to describe inflammation of hair follicles. However, the precise cause of this condition is unknown. It’s classified as a form of alopecia called cicatricial alopecia. This is better known as balding with scars.

Alopecia and folliculitis don’t always occur at the same time. In fact, according to the Mayo Clinic, folliculitis usually occurs by itself. It can affect any portion of the skin, but it doesn’t lead to hair loss like FD can.

Folliculitis is also caused by a bacterial or fungal infection. Unlike FD, traditional folliculitis causes much smaller acne-like lesions. These may come in the form of small red bumps or whiteheads. Over time, the infection may spread and cause widespread sores.

Still, FD is different. In addition to inflamed hair follicles, it can halt hair growth. As the condition progresses, your hair follicles are destroyed and can no longer produce hairs. Bacteria may become trapped in the follicles, leading to pustules. Scar tissue develops in place of dead hair follicles. This prevents any further hair growth in the affected areas.

FD can happen to anyone, even if those who are in overall good health. This condition can affect women and men as early as adolescence. However, no other risk factors are known. While alopecia and folliculitis are contributing factors, there’s no single cause of FD.

Like other types of hair loss, FD is diagnosed and treated by a dermatologist. This type of medical doctor specializes in diseases of the hair and skin. Depending on your insurance, you may need a referral from your primary care doctor if you haven’t seen a dermatologist for this condition before. Your primary care doctor will perform a physical exam of the patches in question and make this determination.

Once you see a dermatologist, they’ll look at your hair and skin more thoroughly. They’ll examine the skin and note any rashes or scarring. Additionally, they’ll look at areas of pustules and thinning hair. All of these symptoms combined could lead to a diagnosis of FD.

Still, it’s important for your dermatologist to rule out other causes of hair loss, such as:

Once these are ruled out as causes of your hair loss based on your medical history, your dermatologist might recommend a biopsy. This procedure involves taking a small sample of your scalp or your skin. A blood test may also be ordered to help rule out any other underlying issues, such as thyroid disease.

Diagnosing FD can take time. Ultimately, the diagnosis is based on a combination of the following:

  • medical history check
  • questionnaire
  • physical exam
  • possible biopsy
  • blood test

There is currently no cure for FD. The main goal of treatment is to prevent the condition from getting worse. Controlling FD depends greatly on medications that can help manage the spread of inflammation. In turn, you may notice fewer symptoms, pustules, and hair loss.

Currently, medications are the preferred treatment methods. Your doctor may recommend one or more of the following:

  • antibiotics to control pustules and infections from open sores
  • isotretinoin (Myorisan, Claravis), a prescription form of vitamin A that’s used for severe acne
  • oral corticosteroids to reduce inflammation and its spread
  • photodynamic therapy, which involves the use of a photosensitizing drug along with exposure to light

People with FD are at risk for scarring and permanent hair loss in the affected areas of the body. Sometimes this is condensed to patches of skin. In more serious cases, widespread baldness and scarring may occur.

Since there’s no cure for FD, it’s important to seek treatment early to prevent the condition from progressing.