Pseudofolliculitis barbae (PFB) is a persistent irritation caused by shaving. It was first described in 1956. Signs and symptoms
Related conditions
Razor burn is a less serious condition caused by shaving, characterized by mild to moderate redness and irritation on the surface of the skin. Unlike PFB, it is usually transient and there is no infection involved. There is also a condition called folliculitis barbae. The difference between the two is the cause of the inflammation in the hair follicles. Where folliculitis barbae is caused by viral or bacterial infections, pseudofolliculitis is created by irritation from shaving and ingrown hairs. Pseudofolliculitis nuchae, a related condition, occurs on the back of the neck, often along the posterior hairline, when curved hairs are cut short and allowed to grow back into the skin. Left untreated, this can develop into acne keloidalis nuchae, a condition in which hard, dark keloid-like bumps form on the neck. Both occur frequently in black men in the military. Here it is so common that services often have known protocols for management. Cause
Pseudofolliculitis barbae (PFB) is most common on the face, but it can also happen on other parts of the body where hair is shaved or plucked, especially areas where hair is curly and the skin is sensitive, such as genital shaving (more properly termed pseudofolliculitis pubis or PFP).After a hair has been shaved, it begins to grow back. Curly hair tends to curl into the skin instead of straight out of the follicle, leading to an inflammation reaction.
A possible complication arises through the fact that cancerous tumors may be more difficult to detect in women with fibrocystic changes. Breast cancer risk
Breast cancer risk is elevated in a defined fraction of the lesions. Except for people with a strong family history of breast cancer, where the risk is two-fold, nonproliferative lesions have no increased risk. Proliferative lesions also have approximately a two-fold risk. In particular, atypical hyperplasia which is associated with an increased risk of developing breast cancer. Theres two types of atypical hyperplasia: lobular and ductal; the lobular type is associated a greater cancer risk of approximately 5-fold and especially high relative risk in premenopausal women. Atypical ductal hyperplasia is associated with 2.4-fold risk. In contrast, a New England Journal of Medicine article  states that for women with a strong familial history of breast cancer, the risk of future breast cancer is roughly doubled, independent of histological status. The article further states "The relative risk of breast cancer for the cohort was 1.56 (95 percent confidence interval, 1.45 to 1.68), and this increased risk persisted for at least 25 years after biopsy. The relative risk associated with atypia was 4.24 (95 percent confidence interval, 3.26 to 5.41), as compared with a relative risk of 1.88 (95 percent confidence interval, 1.66 to 2.12) for proliferative changes without atypia and of 1.27 (95 percent confidence interval, 1.15 to 1.41) for nonproliferative lesions.