Acne and Alopecia Areata: Does the hair help prevent acne?

Hair Follicles in the Prevention of Acne

Many patients with alopecia areata note that they develop acne and acne-like lesions. In some cases this is related to the use of steroid, but in other cases it may be related to the lack of hair itself. This has been proposed for over 70 years.

In order to understand how hair could have a role in acne development, it is important to understand the function of hair. During the process of normal skin turnover, the shed skin cells from the hair follicle epithelium are carried upward in the follicular canal towards the skin surface. It is thought that the sebum that is secreted by the sebaceous glands helps in this process but helping the shed cells efficiency move out of the hair follicle canal.

Ringrose and colleagues first reported the relationship between acne and alopecia areata in 1952. They described a male patient who developed acne, milia and cystic type eruptions only in the areas of alopecia. The authors proposed that the hair helps keep the follicular orfice open to allow sebaceous contents to be properly removed. They descrbied the hair follicle as a “natural drain” to the removal of sebum.

These same authors performed some interesting histological studies by examining biopsies of these acne lesions. They found that acne lesions were not seen in areas that contained hair and were not seen in areas where the pilosebaceous unit was completely degenerated. The proposal here was the acne lesions of alopecia areata represented a transition period - between normal growth patterns and complete loss.

in 2007, Sergeant and colleagues proposed that the hair follicle acts as a type of ‘wick’ and acts to draw sebum up towards the skin surface. They stated that the hairs on the scalp may do this more efficiently that hairs on the face and therefore the hairs on the face may be predisposed to the formation of “micocomedones” and the typcial lesions of acne. Microcomedones are a prerequisite for the ultimate acne lesion.

The authors draw interesting observations that even in the case of patients applying topical steroids, acne-like lesions are often seen only in the alopecic areas and not in the immediately adjacent areas that contain hair - even though these areas likely have received some amount of steroid as well.

Conclusion

Many patients with alopecia areata have concerns about acne lesions. For some, these inflammatory lesions occur on the scalp and may be due to the comedogenic properties of the topical steroids or minoxidil they are applying. For others however, the development of acne eruptions may be due to lack of proper sebum removal and the formation of microcomedones that results from loss of hair follicles.

Reference

Sergeant A, et al. Does hair prevent acne? Insights from alopecia areata. Clin Exp Dermatol. 2007.

Ringrose EJ, et al. Alopecia areata, acne, and milia; report of a unique case illustrating the importance of hair as a natural drain. AMA Arch Derm Syphilol. 1952.