Dermal Microflora Restoration With Ammonia-Oxidizing Bacteria Nitrosomonas Eutropha in the Treatment of Keratosis Pilaris: A Randomized Clinical Trial.

Keratosis pilaris (KP) is a common skin finding that presents as follicular hyperkeratotic papules on the proximal extremities in patients with a propensity for atopy. Although often asymptomatic, the stippled appearance is cosmetically disturbing to patients and difficult to treat as current therapies are limited in availability and efficacy. Nitric oxide (NO) has been found to be essential in basic systemic and cutaneous physiologic function, specifically in terms of its anti-microbial and anti-inflammatory properties, which evolutionarily was maintained by ammonia-oxidizing bacteria (AOB). As modern hygiene practices have improved, there has been a gradual loss of cutaneous AOB and, therefore, the availability of an important source of human physiologic NO. We propose that restoring this dermal microflora with a purified strain of AOB, Nitrosomonas eutropha (D23), may reduce the overall cutaneous inflammatory state and, thus, be a potential therapeutic option for improving the cosmetic appearance of a skin condition such as KP which is often found in association with xerosis and atopic dermatitis. Clinical trial registry number: NCT03243617 J Drugs Dermatol. 2018;17(3):285-288. .