Overview

An ingrown hair occurs when a shaved or tweezed hair grows back into the skin. It can cause inflammation, pain and tiny bumps in the area where the hair was removed.

Ingrown hair is a common condition that results from hair removal. It's most prevalent in black men who shave facial hair. But ingrown hair can affect anyone with tightly curled hair who shaves, tweezes or waxes to remove hair.

Often, an ingrown hair improves without treatment. You can avoid ingrown hair by not removing hair. If that's not an option, you can use hair removal methods that lessen the risk of developing ingrown hairs.

Symptoms

Ingrown hairs most commonly appear in males in the beard area, including the chin and cheeks and, especially, the neck. They can appear on the scalp in males who shave their heads. In females, the most common areas for ingrown hairs are the armpits, pubic area and legs.

Signs and symptoms include:

  • Small, solid, rounded bumps (papules)
  • Small, pus-filled, blister-like lesions (pustules)
  • Skin darkening (hyperpigmentation)
  • Pain
  • Itching
  • Embedded hairs

When to see a doctor

An occasional ingrown hair isn't cause for alarm. See your doctor if:

  • Ingrown hairs are a chronic condition. Your doctor can help you manage the condition.
  • You're a woman with ingrown hairs as a result of excessive unwanted hair growth (hirsutism). Your doctor can determine whether your excess hair is a result of treatable hormonal abnormalities, such as polycystic ovary syndrome.

Causes

Hair structure and direction of growth play a role in ingrown hairs. A curved hair follicle, which produces tightly curled hair, is believed to encourage the hair to re-enter the skin once the hair is cut and starts to grow back. Shaving creates sharp edges in this type of hair, especially if the hair is dry when shaved.

You might also get an ingrown hair if you:

  • Pull your skin taut during shaving — which allows the cut hair to draw back into the skin and re-enter the skin without first growing out
  • Tweeze — which also can leave a hair fragment under the skin surface

When a hair penetrates your skin, your skin reacts as it would to a foreign body — it becomes inflamed.

Risk factors

Having tightly curled hair is the main risk factor for ingrown hairs.

Complications

Chronic ingrown hairs can lead to:

  • Bacterial infection (from scratching)
  • Skin darkening (hyperpigmentation)
  • Permanent scarring (keloids)
  • Pseudofolliculitis barbae, also known as razor bumps

Prevention

To help prevent ingrown hairs, avoid shaving, tweezing and waxing, if possible. If that's not an option, use these tips to make ingrown hairs less likely:

  • Wash your skin with warm water and a mild facial cleanser before shaving.
  • Apply lubricating shaving cream or gel a few minutes before shaving to soften the hair.
  • Use a sharp razor every time you shave. Further study is needed to determine whether a single- or multiple-blade razor is best for preventing ingrown hair. See what works best for you.
  • Avoid close shaves.
  • Don't pull your skin taut while shaving.
  • Figure out which direction to shave in. Generally, men with razor bumps  have been advised to shave in the direction of hair growth. But a study found that men who shaved against the grain saw their rashes improve. Experiment to see what works for you.
  • Rinse the blade after each stroke.
  • Rinse your skin and apply lotion after you shave.

The following hair removal methods also may help prevent ingrown hairs:

  • Electric razor or clipper. With the razor, avoid the closest shave setting and hold the razor or clipper slightly away from your skin.
  • Chemical hair remover. The chemicals in hair-removing products (depilatories) may irritate your skin, so test on a small area first.
  • A cream to decrease hair growth. A product called eflornithine  (Vaniqa) is a prescription cream that decreases hair regrowth when combined with another hair removal method, such as laser therapy. Further study is needed to prove the usefulness of this method.
March 13, 2015
References
  1. Dorland's Illustrated Medical Dictionary. 32nd ed. Philadelphia, Pa.: W.B. Saunders; 2011. http://www.dorlands.com/index.jsp. Accessed Jan. 27, 2015.
  2. Pseudofolliculitis barbae. The Merck Manual Professional Edition. http://www.merck.com/mmpe/print/sec10/ch124/ch124d.html. Accessed Dec. 5, 2014.
  3. Goldstein BG, et al. Pseudofolliculitis barbae. http://www.uptodate.com/home. Accessed Jan. 27, 2015.
  4. Alexis A, et al. Folliculitis keloidalis nuchae and pseudofolliculitis barbae: Are prevention and effective treatment within reach? Dermatologic Clinics. 2014;32:183.