Folliculitis - Possible causes, types and potential treatments

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• Fungal folliculitis
• Bacterial folliculitis
• Viral folliculitis
• Parasitic folliculitis
• Folliculitis related to nutritional deficiency
• Irritants and insults that cause folliculitis
• Actinic folliculitis

Folliculitis is an inflammation around the hair follicle that produces pus. Folliculitis only effects the epidermis, the most superficial layers of skin. Many people believe that pus indicates that presence of bacteria, but pus is actually a collection of white blood cells. Pus usually indicates that the body is trying to fight an infection, but pus can appear in the follicle as a response to non-infectious insults. Most cases of infectious folliculitis are caused by bacteria, but molds, fungi and even viruses and parasites can cause folliculitis. There are also many causes of non-infectious folliculitis ranging from folliculitis caused by shaving to nutritional deficiencies.

Fungal folliculitis

Fungal folliculitiscandidal folliculitis

Dermatophytes are the same organisms that cause athletes foot, jock itch, and cradle cap. The prototypical example of a dermatophyte is Trichophyton rubrum.

Pityrosporum folliculitis is more common in teenage boys and men and is often the cause of pus filled boils on the back, shoulders, and torso. While Candida infections are quite common (e.g. nappy rash, yeast infections), candidal folliculitis is actually quite rare and usually occurs in people who abuse drugs or have immune deficiency.

Dermatophytic folliculitis is treated with topical or oral antifungal medications. Many treatments can be resistant to topical treatments however, and many patients require treatment with drugs such as griseofulvin or terbinafine. Pityrosporum folliculitis, on the other hand, usually responds to a topical antifungal medication such as ciclopirox olamine cream, econazole cream, alcohol/salicylic acid solution and selenium sulfide shampoo. While it is usually unnecessary, pityrosporum folliculitis responds rapidly and dramatically to oral antifungal drugs such as ketoconazole or itraconazole. Candidal folliculitis can be treated with oral itraconazole

Bacterial folliculitis

The most common causes of bacterial folliculitis are caused by bacteria that normally inhabit the skin, such as Staphylococcus aureus and various species of Streptococcus such as S. pyogenes. Other bacteria that can cause folliculitis are Pseudomonas, Proteus, E. coli and, Aeromonas hydrophila. Pseudomonas and Aeromonas hydrophila folliculitis are often caused by contaminated water, such as may be found in un-chlorinated pools or spas.

Most cases of bacterial folliculitis will respond without specific treatment. In fact, there are no randomised, controlled clinical trials investigating treatments for folliculitis.

Warm compresses applied to the affected area may help relieve symptoms, such as itchiness.

Sufferers may try topical antibiotics, since most cases are caused by Staphylococcus aureus, although it is unclear whether topical antibiotics shorten the duration of the infection. Triple antibiotic ointment appears to be more potent and more broadly effective then mupirocin, even among drug-resistant bacterial strains that commonly occur.

Viral folliculitis

Viral folliculitis is usually due to the herpes simplex virus or molluscum contagiosum and is relatively rare (though skin infection from these viruses is fairly common). When viral folliculitis occurs, it often occurs in people with immune system deficiency, such as HIV/AIDS. Treatment for herpes folliculitis is usually a short course of the antiviral drug, aciclovir. Folliculitis caused by the molluscum contagiosum virus is aimed at destroying pustules with the topical application of acid (e.g. trichloroacetic acid), cutting away the lesion, or freezing.

Parasitic folliculitis

Certain skin mitesDemodex brevis

Folliculitis related to nutritional deficiency

Severe deficiencies in vitamin C or vitamin A may result in the follicular reaction that resembles folliculitis. Deficiencies in these vitamins are rare in developed nations and require deficiencies of two months or more before folliculitis appears. Replenishing the nutritional deficiency with the corresponding vitamin will reverse the folliculitis.

Irritants and insults that cause folliculitis

Several activitiesfolliculitis

Razor burn that can occur after shaving may leave pustules that resemble folliculitis; however, this is more accurately called pseudofolliculitis.

Various chemicals and medications can cause folliculitis, though it may be difficult to determine the precise cause and most people. Topically applied medications or chemicals that contact the skin in the affected area are strong candidates.

The most effective way to treat pseudofolliculitis is to stop shaving, though this may undesirable for many people for cosmetic or occupational reasons. In these cases, people with pseudofolliculitis may need to change their shaving habits by using additional shaving cream during shaving or shaving cream with special lubricants. Hair removing chemicals (i.e. depilatories), electrolysis, and laser hair removal may be suitable alternatives to shaving and may help improve pseudofolliculitis.

Actinic folliculitis

Some people develop folliculitis after periods of intense sun exposure, a condition called actinic folliculitis. Even though non-infectious folliculitis is not caused by the microorganism, it does represent an abnormal inflammation of the hair follicle. Therefore, it can usually be successfully treated with topical steroids and/or nonsteroidal anti-inflammatory drugs (NSAIDs). Ironically, excessive application of corticosteroids is actually a risk factor for bacterial folliculitis, because it can suppresses the body's immune system and makes the skin vulnerable to bacterial infection. Nevertheless, modest amounts of low potency corticosteroids can be quite helpful for most causes of non-infectious folliculitis. Actinic folliculitis may be minimised or even prevented by using sunscreen prior and during sun exposure.

References

1. Chiller K, Selkin BA, Murakawa GJ. Skin microflora and bacterial infections of the skin. J Investig Dermatol Symp Proc. Dec 2001;6(3):170-174. doi:10.1046/j.0022-202x.2001.00043.x
2. Ratnam S, Hogan K, March SB, Butler RW. Whirlpool-associated folliculitis caused by Pseudomonas aeruginosa: report of an outbreak and review. J Clin Microbiol. Mar 1986;23(3):655-659.
3. Julia Manresa M, Vicente Villa A, Gene Giralt A, Gonzalez-Ensenat MA. Aeromonas hydrophila folliculitis associated with an inflatable swimming pool: mimicking Pseudomonas aeruginosa infection. Pediatr Dermatol. Sep-Oct 2009;26(5):601-603. doi:10.1111/j.1525-1470.2009.00993.x
4. Suzuki M, Yamada K, Nagao M, et al. Antimicrobial ointments and methicillin-resistant Staphylococcus aureus USA300.
5. Jones RN, Li Q, Kohut B, Biedenbach DJ, Bell J, Turnidge JD. Contemporary antimicrobial activity of triple antibiotic ointment: a multiphased study of recent clinical isolates in the United States and Australia. Diagnostic Microbiology and Infectious Disease.54(1):63-71. doi:10.1016/j.diagmicrobio.2005.08.009
6. Luelmo-Aguilar J, Santandreu MS. Folliculitis: recognition and management. Am J Clin Dermatol. 2004;5(5):301-310.
7. Jones HE, Reinhardt JH, Rinaldi MG. A clinical, mycological, and immunological survey for dermatophytosis. Arch Dermatol. Jul 1973;108(1):61-65.
8. Smith KJ, Neafie RC, Skelton HG, 3rd, Barrett TL, Graham JH, Lupton GP. Majocchi's granuloma. J Cutan Pathol. Feb 1991;18(1):28-35.
9. Viana de Andrade AC, Pithon MM, Oiticica OM. Pityrosporum folliculitis in an immunocompetent patient: clinical case description. Dermatol Online J. Aug 2013;19(8):19273.
10. Hald M, Arendrup MC, Svejgaard EL, Lindskov R, Foged EK, Saunte DM. Evidence-based Danish Guidelines for the Treatment of Malassezia-related Skin Diseases. Acta Derm Venereol. Jan 15 2015;95(1):12-19. doi:10.2340/00015555-1825
11. Jang KA, Kim SH, Choi JH, Sung KJ, Moon KC, Koh JK. Viral folliculitis on the face. Br J Dermatol. Mar 2000;142(3):555-559.
12. Nieboer C. Actinic superficial folliculitis; a new entity? Br J Dermatol. May 1985;112(5):603-606.