Folliculitis

Folliculitis is an infection or inflammation of one or more hair follicles. While folliculitis can occur anywhere on the skin where hair grows, it most commonly occurs in places where skin is exposed to increased friction. This includes the thighs, buttocks, neck, and armpits. Because it is dependent on the presence of hair, folliculitis specifically does not occur on the palms of the hands or the soles of the feet. It typically presents as small bumps that often resemble acne or a simple rash. Folliculitis can be acute or chronic and may affect a single hair follicle or many follicles. Although folliculitis is a common condition that can affect anyone, it is more frequently seen in people who are obese. Folliculitis resolves on its own in most cases but can also be treated with oral or topical antibiotics or antifungal medications. NSAIDs (anti-inflammatory medications) may also be prescribed to relieve pain or itching.

Background

Hair follicles are pocket-like structures found in the dermis and epidermis, the top two layers of the skin. These follicles surround the root of a hair and contain various cells and connective tissues. Hair follicles can be found all over the surface of most of the skin on the human body. There are roughly one hundred thousand hair follicles on the scalp alone. As a result, hair follicles are a key part of human anatomy despite their small size.

Hair follicles have a relatively simple anatomical structure, which includes four main parts: the papilla, germinal matrix, bulb, and bulge. The papilla is a network of connective tissues and blood vessels that provides growing hair with nourishment. It is located at the base of the follicle. The germinal matrix is the part of the follicle where new hairs are produced by cells as old hairs gradually die and fall out. Like the papilla, the germinal matrix is near the base of the follicle. The bulb is a rounded structure at the bottom of the follicle that surrounds the papilla and germinal matrix. The bulb represents the living part of a hair. The part of the hair that is visible above the surface of the skin is already dead. The bulb houses various stem cells that divide every 23 to 72 hours. Hormones in the bulb help regulate hair growth and structure at different key stages of a person’s life, including during puberty and pregnancy. The bulge is in the middle section of the follicle. It houses stem cells that regenerate new follicles, the sebaceous glands, and the epidermis. In addition, the bulge serves as the insertion point of the arrector pili, a small band of muscle tissue that causes hair to stand on end when a person has goosebumps.

Hair follicles are primarily responsible for hair growth. On average, hair typically grows at a rate of approximately one-half inch per month. Hair follicles also help determine the texture and color of a person’s hair. While hair can regrow if it is pulled out of the follicle, damaged follicles may stop producing hair. A number of conditions can affect the function of hair follicles, one of which is folliculitis.

Overview

Folliculitis is the infection or inflammation of one or more hair follicles. It results in the appearance of small crusty bumps on the surface of the skin. These bumps are often red in color but can also be white or yellow and may produce pus. A person with folliculitis may also experience soreness, itching, and swelling. In any case, the symptoms associated with folliculitis are generally mild and do not present any serious health risks.

Folliculitis occurs when hair follicles are damaged or blocked. Such damage or blockage may result from wearing tight clothing, skin injuries related to shaving, not showering after excessive sweating, or having a weakened immune system. Damaged or blocked follicles are at an increased risk of becoming infected by bacteria or fungi. There are two main types of bacterial folliculitis: Staphylococcus aureus and Pseudomonas aeruginosa folliculitis. One of the most common forms of folliculitis, Staphylococcus aureus folliculitis results in the formation of a small red or white pimple filled with pus. Pseudomonas aeruginosa folliculitis is also known as “hot tub” folliculitis because that particular form of bacteria thrives in heated, moving water. People usually get Pseudomonas aeruginosa folliculitis after they have been in a hot tub or on a water slide where the bacteria is present. Malassezia folliculitis is the most common form of fungal folliculitis. It causes an itchy, acne-like breakout that may be aggravated by sweat. Pseudofolliculitis barbae and Sycosis barbae are shaving-related forms of folliculitis that arise when the sharply trimmed edges of beard hair turn back into the skin and cause irritation. Gram-negative folliculitis occurs with prolonged use of antibiotics taken to treat acne. Eosinophilic folliculitis occurs in patients with a weakened immune system. A deeply infected follicle may lead to the formation of a boil. The formation of multiple boils in one area leads to carbuncles.

Most cases of folliculitis eventually resolve on their own and do not lead to more serious problems. However, several options exist for treating folliculitis when medical intervention is required. Patients with acute cases of folliculitis that are particularly severe or slow to heal may be prescribed oral or topical antibiotics or antifungal medications designed to treat the cause of the infection. Physicians may also prescribe NSAIDs to treat pain or itching related to folliculitis. Patients with chronic folliculitis may ultimately be required to undergo laser hair removal.

Some measures can be taken to prevent folliculitis. One is to shave only in the direction that hair grows or simply use an electric razor instead of a manual razor. It may also be helpful to avoid tight-fitting clothes and lotions that clog pores. It is also a good idea to shower after heavy sweating and avoid sharing personal hygiene products with others. Those who have folliculitis can also lessen the severity of their condition and prevent complications by avoiding friction in the infected area, using only clean towels and washcloths, and using warm compresses to soothe irritation and reduce pain.

Bibliography

Brannon, Heather L. “The Structure and Growth Cycle of Hair Follicles.” VeryWellHealth, 15 Oct. 2019, www.verywellhealth.com/hair-follicle-1068786. Accessed 28 Feb. 2020.

Ferguson, Sian. “How Do Hair Follicles Function?” Healthline, 13 Feb. 2019, www.healthline.com/health/hair-follicle. Accessed 28 Feb. 2020.

Fischer, Kristen. “Folliculitis.” Healthline, 27 July 2016, www.healthline.com/health/folliculitis. Accessed 28 Feb. 2020.

“Folliculitis.” Cleveland Clinic, 2020, my.clevelandclinic.org/health/diseases/17692-folliculitis-. Accessed 28 Feb. 2020.

“Folliculitis.” MedlinePlus, 2020, medlineplus.gov/ency/article/000823.htm. Accessed 28 Feb. 2020.

Gardner, Stephanie S. “What Is Folliculitis?” WebMD, 2 Nov. 2018, www.webmd.com/skin-problems-and-treatments/what-is-folliculitis#1. Accessed 28 Feb. 2020.

Oakley, Amanda. “Folliculitis.” DermNet NZ, Apr. 2014, dermnetnz.org/topics/folliculitis. Accessed 28 Feb. 2020.

Satter, Elizabeth K. “Folliculitis.” Medscape, 15 Aug. 2019, emedicine.medscape.com/article/1070456-overview. Accessed 28 Feb. 2020.