What Causes Ingrown Pimples?

An ingrown pimple is one possible complication related to ingrown hairs, which occur when a hair shaft curls as it grows and re-enters the follicle from which it originates, according to Stephen M. Schleicher, MD's "Skin Sense!: A Dermatologist's Guide to Skin and Facial Care." There are multiple root causes of ingrown hairs that may lead to ingrown pimples, but you can avoid many of them through a gentle and thorough skin and hair care regimen.

Shaving

Ellen Marmur, MD and Gina Way's "Simple Skin Beauty: Every Woman's Guide to a Lifetime of Healthy, Gorgeous Skin" states that ingrown pimples frequently develop in recently shaved areas, especially those that are shaved very close and against the grain of the hair. This happens because shaving can make hair shaft ends very sharp, which makes it easier for them to re-enter the follicle. Shaving against the grain can also train hairs to curl backward, increasing the odds that they will become ingrown. Electric razors and special razors with bump guards or soothing strips, when used to shave with the grain, may help reduce the instances of ingrown pimples caused by shaving.

Naturally Curly Hair

Naturally curly and coarse hair is the most likely hair type to cause ingrown hairs and pimples, according to WomenFitness.net. For the same reason that it is best to shave with the grain, curly hair tends to be more problematic simply because its natural growth pattern is more likely to direct a growing hair shaft back into its follicle. While there is nothing that can be done to make naturally curly or coarse hair less so, you can help minimize ingrown pimples and hairs by shaving carefully as described above and by regularly exfoliating your skin. Marmur and Way's book recommends frequent exfoliation to keep the follicles clean and open, making it easier for hairs to grow out properly, but suggests that you not exfoliate skin that already has ingrown pimples so as to avoid irritation.

Folliculitis

The Palo Alto Medical Foundation cites folliculitis as a common complication of ingrown hairs. According to the Mayo Clinic, folliculitis is an infection of a hair follicle typically caused by Staphylococcus aureus. The condition appears as one or more white head pimples located in the centers of hair follicles, and may also produce redness, itching, pain and oozing pus. Folliculitis may develop as a result of excessive sweating, skin wounds, chafing clothing and other skin conditions. Most cases are mild and improve on their own, and may be helped by non-prescription hydrocortisone and antibacterial creams and ointments. Consult with your physician about severe or chronic cases, which may require prescription topical aids.