Can pregnancy be the cause of keratosis pilaris?

Affecting over a quarter of the global population, keratosis pilaris falls into the category of dermatoses harmless to health but can prove bothersome for some individuals. It is caused by an obstruction of the hair follicles, leading to the emergence of small bumps on the skin's surface. This obstruction is the result of a disruption in the keratinisation process and an excessive production of keratin. This surplus is also the cause of the accumulation of dead cells, hence the thickening and irregularity of the skin.

The small bumps associated with keratosis pilaris typically appear on the arms and legs and give the skin an appearance similar to that of gooseflesh. In some cases, they may be present on the face or scalp, but this is rather rare. To date, even though the precise causes of the keratosis pilaris are still under investigation, several factors have been identified as potentially contributing to its development. Does pregnancy have an impact?

Pregnancy is synonymous with significant changes and can significantly impact the skin. Acne flare-ups, spider angiomas, melasma... The consequences are diverse and related to hormonal fluctuations that pregnant women undergo. As for keratosis pilaris, the evidence is incomplete but some studies suggest a hormonal influence in the pathogenesis of this disease. A recent study conducted with 5 pregnant women presenting with keratosis pilaris highlighted an intensification of symptoms during pregnancy, as well as their improvement after childbirth.

Other scientists have reported the case of a 29-year-old woman, with no history of keratosis pilaris, who developed hyperkeratotic follicular papules on the right side of her face, neck, trunk, arms and legs, accompanied by mild itching, during her second month of pregnancy. The study concluded after the participant gave birth, but no spontaneous improvement was observed. The researchers concluded that this unusual case because it was unilateral of keratosis pilaris showed that the onset and severity of this condition could be associated with the hormonal changes of pregnancy, without however the biological mechanism at work being explained.

It has been suggested in other studies that theincrease in androgen levels in the body during pregnancy could be the cause of the development of keratosis pilaris. Indeed, it seems that these steroidal hormones influence the maturation of keratinocytes, the cells that produce keratin, which could then cause a hyperkeratinisation of the pilosebaceous unit of terminal hairs. This excess keratin would then lead to the obstruction of hair follicles, a phenomenon at the origin of keratosis pilaris. It is important to note that this is a hypothesis that still requires further research to be confirmed.

Note : It is important to exercise caution regarding the impact of pregnancy on keratosis pilaris. To date, far too few studies have been conducted on this subject, and those that have shown interest have involved very few participants.

• SCHWARTZ R. A. & co. Keratosis Pilaris: A Widespread Follicular Hyperkeratosis. Paediatric Dermatology (2008).

• ZHENG M. & al. Unilateral Generalised Keratosis Pilaris Following Pregnancy. Cutis (2014).

• WANG J. F. & ORLOW S. J. Keratosis Pilaris and its Subtypes: Associations, New Molecular and Pharmacologic Etiologies, and Therapeutic Options. American Journal of Clinical Dermatology (2018).