Folliculitis

There are two basic categories of cause of folliculitis, infections and all other causes of hair follicle inflammation.

• Infections by bacteria (Staphylococcus aureus for example), fungi (yeasts and dermatophytes), viruses (herpes simplex), and parasites (Demodex mites) can cause folliculitis.
• Noninfectious causes of folliculitis include topical irritants (insoluble cutting oils are an example), physical irritants (hair extraction), certain drugs, teenage pimples (acne vulgaris), and certain auto-inflammatory conditions (folliculitis decalvans).

Folliculitis does not occur on the palms or soles or on mucous membranes, since they have no hair follicles.

• Exposure to potential infectious agents and certain types of occupational exposures can predispose to folliculitis.
• Football players and wrestlers are predisposed to develop staphylococcal folliculitis due to the presence of superficial skin abrasions related to their athletic participation.
• There is a well-known condition called "hot tub folliculitis" which can affect those who frequent poorly maintained hot tubs. These people develop a folliculitis produced by Pseudomonas bacteria.
• Poor shaving techniques can produce folliculitis on the legs of women and the necks of men.
• Pregnant women are prone to develop an itchy folliculitis that resolves spontaneously after delivery.
• Patients with HIV disease may develop a peculiar folliculitis produced by certain white blood cells (eosinophils) infiltrating into the follicles as well as a widespread folliculitis produced by molluscum contagiosum virus.
• A group of new anticancer drugs, epidermal growth factor receptor inhibitors, can produce a facial folliculitis.

The characteristic finding in folliculitis is

• redness,
• swelling, and
• often pustule formation limited to hair follicles.

It may be possible to identify a hair surrounded by red, swollen tissue.

• Occasionally this may be associated with itching and mild pain or tenderness.

Virtually all human beings experience folliculitis at some time in their lives with the vast majority of cases spontaneously resolving. So medical care should be sought only if the condition persists and starts to hinder normal daily activities.

• Bacterial folliculitis can produce deeper abscesses commonly called boils which often require a draining procedure and/or oral antibiotics.
• If caused by an antibiotic-resistant bacteria (MRSA, or methicillin-resistant S. aureus), the doctor may have to culture the pus to determine the correct drug to prescribe.

Since there are so many causes of folliculitis, precision in diagnosis is often difficult. If it becomes necessary to see a physician, it is often essential to culture for microorganisms and occasionally to perform a biopsy of the follicular tissue for pathologic examination.

• For noninfectious causes, it is critical to obtain a history that accurately implicates exposure to an inciting agent.
• Certain auto-inflammatory conditions may have a characteristic clinical appearance that the physician can recognize.

Treatment depends on the diagnosis. It is very important not to miss a diagnosis caused by an infectious organism because these infections can often be cured by the appropriate medication.

• Folliculitis produced by poor shaving technique can be treated with weak topical steroids like 1% hydrocortisone cream.
• Bacterial folliculitis can be treated with antibacterial skin washes and topical antibiotics
• Fungal folliculitis can be treated with an antifungal shampoo or body wash.
• Persistent skin discoloration can be treated with prescription fading creams like hydroquinone 4%.

It is important to avoid manipulating an area of folliculitis because this can produce additional tissue damage, change the appearance of the eruption to make it unrecognizable to the doctor, and force microorganisms more deeply into the skin.

One should wash the skin with soap and water soon after participating in any activity that might result in exposure to pathogenic microorganisms. Reducing exposure whenever possible to exogenous agents like drugs or topical substances that might be implicated would be prudent.

Most patients recover from folliculitis completely. There can be occasional recurrences.