The symptoms of hidradenitis suppurativa (HS), also known as acne inversa, may appear similar to those of other conditions. Folliculitis, in particular, may sometimes be confused with HS. Both conditions cause swollen, fluid-filled lumps to appear on the skin. These lumps may be red and painful.

Despite their similarities, HS and folliculitis are distinct conditions with their own causes and treatments. Although the differences between folliculitis and HS should be clear to a doctor or dermatologist, it may help you to understand the differences between their symptoms, causes, and treatments.

What Is Folliculitis?

Folliculitis is a skin disease characterized by inflammation of a hair follicle. The hair follicle is a small space or opening around the root of a hair. Every hair on the human body has its own follicle. The inflammation seen in folliculitis can cause swelling and pain at the affected follicle, as well as the accumulation of white or yellowish pustules (fluid-filled bumps) that look similar to acne.

Some cases of folliculitis clear up with antibiotics or other treatments, and others last for a long time. Long-lasting or persistent folliculitis is called chronic folliculitis.

Are Folliculitis and Hidradenitis Suppurativa Related?

Although the relationship between the two conditions is not yet understood, many people diagnosed with HS also experience folliculitis. Folliculitis can occur in the same areas affected by HS (the apocrine-bearing areas, or areas that produce a high volume of sweat) or in other unrelated locations. HS usually appears under the arms, around the buttocks, and the inguinal folds. Folliculitis can occur additionally on the scalp, beard area, chest, and back.

Some experts believe that HS is often misdiagnosed as folliculitis. Others state that a person can experience both conditions at the same time, at different times, or independently of one another. Some researchers argue that HS should be considered a type of folliculitis, noting that HS has more in common with folliculitis than with any of the other conditions it is often categorized under.

Although research has determined a statistical connection between folliculitis and HS, more study is necessary to understand the particulars of this relationship.

Symptoms of Folliculitis and Hidradenitis Suppurativa

Folliculitis and HS are characterized by bumps on the skin that may itch or burn. These bumps tend to form in areas with high concentrations of sweat glands and frequent skin-on-skin friction, like in the armpits or underarms, inner thighs, or the groin (folliculitis can also occur in other areas of the body). Both folliculitis and HS may also result in infections that require medical treatment.

In its early stages, folliculitis usually appears as a group of tiny bumps on the skin. These bumps may be red or filled with white or yellowish fluid, giving the appearance of whiteheads. If left untreated, a major infection can develop and form a pus-filled bump called a boil or furuncle. If several boils merge together, they form a carbuncle or abscess.

HS, on the other hand, may first appear like blackheads (bumps with dark-colored centers) or as pea-sized lumps under the skin. These bumps don’t go away for weeks and may be painful and itchy. Over time, these lumps may get bigger and ooze fluid and pus. If left untreated, these bumps may form tunnels under the skin (sinus tracts) that continually ooze blood and pus and can lead to extensive scarring.

Causes and Risk Factors of Folliculitis and Hidradenitis Suppurativa

Despite the overlap in some of their symptoms, folliculitis and HS have distinct causes and risk factors.

Folliculitis is usually caused by infection with staphylococcus bacteria (known commonly as a staph infection). This condition can also be caused by other bacterial infections, yeast, viruses, fungal infections, and more. Occasionally, an inflamed hair follicle can trigger folliculitis, but this is less common.

Risk factors for folliculitis include having a compromised immune system, being exposed to bacteria or other substances that can cause the condition, taking certain medications, and having acne or dermatitis.

HS occurs when the apocrine glands become clogged, often when certain types of cells grow too quickly and prevent the body’s naturally occurring oils from escaping. Experts aren’t sure exactly why this growth occurs, although ongoing research is attempting to determine the exact cause. We do know that HS does not occur due to uncleanliness or infection and is most likely an inflammatory process.

Those at risk of developing HS include people with a family history of the condition, people who smoke, those who are overweight or obese, and those who have been diagnosed with certain other conditions (including arthritis, diabetes, inflammatory bowel disease, and metabolic syndrome). Women in their 20s and 30s are at the highest risk of HS. Being African American may also be a risk factor, although studies are ongoing.

Diagnosing Folliculitis and Hidradenitis Suppurativa

The diagnostic process for folliculitis and HS is often similar, particularly at the onset of the skin condition. If your health care provider suspects you have folliculitis or HS, your doctor or dermatologist will take a comprehensive medical history, focusing specifically on your skin diagnosis (or your family’s skin diagnoses) and other diagnoses often related to HS.

A doctor will then perform a thorough examination of the affected areas of skin, noting where your breakouts are located. They will likely ask when your symptoms first appeared, how long the symptoms usually last or have lasted, and whether the symptoms are constant or tend to disappear then reappear.

To aid in the diagnostic process, a doctor may also perform a biopsy (microscopic examination of the affected skin cells). If you have sores, cysts, nodules, pimples, or lesions that are draining fluid or pus, the doctor may take a sample of this fluid to test for any bacteria growing in the area. Finally, your doctor may ask for a blood test, especially if they suspect HS. Certain markers in your blood can indicate that HS is the correct diagnosis rather than folliculitis.

Some doctors prefer to try certain treatments and evaluate how well they work before making a conclusive diagnosis. They may not diagnose HS until treatments for other skin conditions, including folliculitis, have proven ineffective.

Treating and Managing Folliculitis and Hidradenitis Suppurativa

Certain treatment options for folliculitis and HS overlap. Both may be treated with oral antibiotics, topical cream-based antibiotics, and antibacterial soaps. These treatments may clear up the infection once and for all in those with folliculitis. Antibiotics are used to treat the inflammation that has escalated into an infection in those with HS. A low-dose antibiotic may be taken for long periods of time.

Both conditions may also be treated with creams or oral medications designed to fight inflammation, including nonsteroidal anti-inflammatory drugs and corticosteroids.

After that, treatments tend to vary. Folliculitis caused by a fungal infection can be treated with antifungal pills or creams. Minor surgery may be necessary to fully remove the infection in large carbuncles. Recurrent folliculitis may call for laser hair removal.

People with HS may require treatment with biologic medications (such as adalimumab), which are designed to lower the body’s inflammation levels. Other biologic medications are being investigated for HS, as the pathophysiology indicates that some pathway in the immune system leads to HS. HS related to hormones may be controlled by taking hormonal birth control, and retinoids have also proven helpful. In some cases, abscesses may need to be drained, or HS lesions may be treated with a laser to clear them of accumulated fluids. HS can also be treated surgically, removing the affected glands usually as a last resort.

Find Your Team

On myHSteam, the social network for people with hidradenitis suppurativa, more than 23,700 members come together to ask questions, give advice, and share their stories with others who understand life with hidradenitis suppurativa.

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