Folliculitis in Adult
See also in: Anogenital,Hair and ScalpAlerts and Notices
Synopsis

The etiology of folliculitis can be variable, with bacterial, fungal, viral, parasitic, and noninfectious causes reported. A detailed history of comorbid conditions, exposures, and medications, in conjunction with appropriate ancillary testing, can be helpful.
In immunocompetent patients, bacterial folliculitis may be considered, often due to a predisposing factor that allows for increased bacterial burden on the skin surface. Staphylococcus aureus and Streptococcus species are commonly implicated. Predisposing factors include nasal carriage of S. aureus, occlusion, maceration, hyperhydration, complicating pruritic skin diseases, vigorous application of topical medications, shaving (folliculitis barbae / sycosis barbae), exposure to oils and certain chemicals, and exposure to heated or contaminated water.
For example, a history of contaminated water exposure was suspected in an outbreak of folliculitis due to atypical mycobacteria in otherwise healthy adults who had recently undergone pedicures. Folliculitis due to Pseudomonas aeruginosa has similarly been linked to contaminated water exposure from swimming pools.
These predisposing factors have also been associated with infectious folliculitis due to nonbacterial causes. A history of shaving or other hair-removal procedures has been associated with folliculitis due to molluscum contagiosum and dermatophyte infection (tinea barbae), as well as noninfectious folliculitis due to a foreign body reaction (pseudofolliculitis barbae).
Fungal causes of folliculitis in immunocompetent hosts additionally include Pityrosporum (Malassezia) spp. and dermatophyte infection of the hair follicle (including fungal folliculitis and Majocchi granuloma). Pustular folliculitis secondary to Candida spp. (see candidiasis) has also been reported in immunocompetent adults, particularly in skin folds.
Viral folliculitis secondary to varicella zoster virus (usually a primary phenomenon), herpes simplex virus (usually inoculated secondary to shaving), and molluscum contagiosum have been described.
In immunocompromised patients, folliculitis can occur secondary to etiologies similar to those discussed above. For example, bacterial folliculitis may evolve into furunculosis, or inflammation involving deeper aspects of the pilosebaceous unit, in patients with certain risk factors such as diabetes mellitus, immunosuppression, or human immunodeficiency virus (HIV) infection. Fungal folliculitis secondary to Candida albicans has been reported in immunocompromised patients, particularly in the setting of candidemia.
In addition to these etiologies, more esoteric causes must also be kept in mind when considering the immunocompromised host. For example, Demodex spp. are mites that infest the follicles and sebaceous glands of normal adults, but have been associated with a pruritic perifollicular papulopustular eruption on the face of immunocompetent adults or with a more widespread eruption in immunocompromised adults and children. Eosinophilic pustular folliculitis presenting as pruritic urticarial follicular papules is seen in immunocompetent hosts (the Ofuji variant) or in hosts immunosuppressed by HIV infection or hematologic disorders (immunosuppression-associated eosinophilic folliculitis). During pregnancy, a pruritic folliculitis has been reported with no associated morbidity to the fetus or mother and that clears spontaneously after delivery.
A careful medication history is required. Exposure to prolonged periods of antibiotic therapy results in disruption of the normal gram-positive skin flora and is a risk factor for the development of gram-negative folliculitis. Other medications associated with follicular eruptions include corticosteroids, epidermal growth factor receptor inhibitors, sirolimus, cyclosporine, lithium, lamotrigine, aripiprazole, chlorpromazine, dantrolene, dapsone, and halogens (potassium iodide, radiocontrast media).
Codes
ICD10CM:L73.8 – Other specified follicular disorders
SNOMEDCT:
13600006 – Folliculitis
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Diagnostic Pearls
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Differential Diagnosis & Pitfalls
Consider alternative causes and organisms such as:- Pseudomonas folliculitis (hot tub folliculitis)
- Pityrosporum folliculitis
- Malassezia folliculitis
- Demodex folliculitis
- Tinea barbae and tinea capitis
- Majocchi granuloma
- Acne
- Rosacea
- Keratosis pilaris
- Folliculitis due to herpes simplex virus (HSV), varicella zoster virus (VZV; varicella or zoster), or molluscum contagiosum
- Steroid acne
- Pseudofolliculitis barbae
- Insect bites
- Miliaria rubra
- Acne keloidalis nuchae
- Acute generalized exanthematous pustulosis
- Eosinophilic folliculitis
- Perforating folliculitis
- Flat warts
- Milia
- Perioral dermatitis
- Fox-Fordyce disease
- Candidiasis
- Colloid milia
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Management Pearls
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Therapy
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Drug Reaction Data
Below is a list of drugs with literature evidence indicating an adverse association with this diagnosis. The list is continually updated through ongoing research and new medication approvals. Click on Citations to sort by number of citations or click on Medication to sort the medications alphabetically.Subscription Required
References
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Last Reviewed:03/01/2017
Last Updated:03/22/2023
Last Updated:03/22/2023


Overview
Folliculitis is a skin condition caused by an inflammation of one or more hair follicles. It typically occurs in areas of irritation, such as sites of shaving, skin friction, or rubbing from clothes. In most cases of folliculitis, the inflamed follicles are infected with bacteria, especially with Staphylococcus (or "staph") organisms, that normally live on the skin. Bacteria such as Pseudomonas may live in hot tubs, spas, and swimming pools and may also cause folliculitis.Who’s At Risk
Folliculitis occurs in people of all ages, races / ethnicities, and sexes.Further risk factors for folliculitis include:
- Diabetes.
- A suppressed immune system due to HIV, organ transplantation, or cancer.
- An underlying skin condition, such as eczema, acne, or another inflammation of the skin (dermatitis).
- Obesity.
- Frequent shaving.
- Pressure (eg, prolonged sitting on the buttocks).
Signs & Symptoms
The most common locations for folliculitis include the:- Scalp.
- Buttocks.
- Thighs.
- Areas that are shaved, such as the beard area, underarms, groin, and legs.
Mild and moderate cases of folliculitis are often tender and itchy. More severe cases of folliculitis, which may be deeper and may affect the entire hair follicle, can be painful.
Mild and moderate cases of folliculitis usually clear up quickly with treatment and leave no scars. More severe cases of folliculitis may lead to complications such as cellulitis (an infection of the deeper skin tissue), scarring, and permanent hair loss in the affected area.
Self-Care Guidelines
To prevent folliculitis:- Shave in the same direction of hair growth.
- Avoid shaving irritated skin.
- Use an electric razor or a new disposable razor each time you shave.
- Avoid tight, constrictive clothing, especially during exercise.
- Wash athletic wear after each use.
- Consider other methods of hair removal, such as depilatories.
- Use an antibacterial soap or wash (eg, PanOxyl Acne Creamy Wash, Hibiclens).
- Launder towels, washcloths, and bed linens frequently, and do not share such personal items with others.
- Wear loose-fitting clothing.
When to Seek Medical Care
Make an appointment to be evaluated by a dermatologist or another medical professional if the above self-care measures do not resolve the condition within 2-3 days, if symptoms come back frequently, or if the infection spreads.Be sure to tell the medical professional about any recent exposure to hot tubs, spas, and swimming pools, as a less common form of folliculitis may be caused by contamination from these water sources.
If you are currently being treated for a skin infection that has not improved after 2-3 days of antibiotics, return to your medical professional.
Treatments
Folliculitis is fairly easy to diagnose in most cases. Your medical professional may perform a bacterial culture to determine the cause of the folliculitis and may recommend:- Antibacterial wash, such as chlorhexidine (eg, Betasept, Hibiclens).
- Topical antibiotic lotion or gel, such as erythromycin (eg, AkneMycin) or clindamycin (eg, Cleocin T).
- Oral antibiotic pills, such as cephalexin (eg, Keflex) or doxycycline (eg, Vibramycin, Monodox), or ciprofloxacin (eg, Cipro) in the case of hot tub folliculitis.
- A combination of two different oral antibiotics, including trimethoprim-sulfamethoxazole (eg, Bactrim), clindamycin (eg, Cleocin), amoxicillin (eg, Amoxil), linezolid (eg, Zyvox), or tetracycline.
Folliculitis in Adult
See also in: Anogenital,Hair and Scalp