Botulinum toxin-induced resolution of axillary granular parakeratosis

Granular Parakeratosis: A Case Report

Granular parakeratosis is an uncommon acquired keratinization disorder that occurs in the armpit, groin, and other parts of the body. It may be related to stimulation by detergents and antiperspirants. This article reports a case of granular parakeratosis in the groin. The patient was a young man with no predisposing factors. The clinical manifestations included symmetrical bilateral inguinal erythema, dryness, and a small amount of bran-like desquamation. After histopathological examination, the final diagnosis was granular parakeratosis, which was cured by topical application of glucocorticoid cream and silicone oil cream. Granular parakeratosis is a rare skin disease of unknown etiology. Clinicians need to pay attention to this disease and differentiate it from various diseases to avoid misdiagnosis.

Alternative Clinical Indications of Botulinum Toxin

Botulinum toxin type A (BoNTA) is a powerful neurotoxin that inhibits acetylcholine release from presynaptic vesicles. The potency and safety profile of BoNTA grant the toxin vast therapeutic potential. It has been used off-label for a variety of dermatologic conditions. This review aims to analyze published literature regarding the benefits and risks of the off-label use of BoNTA beyond facial lines, including eccrine hidrocystomas, enlarged pores, keloids and hypertrophic scars, hidradenitis suppurativa, hyperhidrosis, masseter muscle hypertrophy, and salivary gland hypertrophy, among others. A MEDLINE search from January 2000 to December 2019 was conducted on the off-label uses of botulinum toxin in dermatology.

Antipruritic Effects of Botulinum Neurotoxins

This review explores current evidence to demonstrate that botulinum neurotoxins (BoNTs) exert antipruritic effects. Both experimental and clinical conditions in which botulinum neurotoxins have been applied for pruritus relief will be presented and significant findings will be highlighted. Potential mechanisms underlying antipruritic effects will also be discussed and ongoing challenges and unmet needs will be addressed.

Granular Parakeratosis: A Comprehensive Review and a Critical Reappraisal

Granular parakeratosis (GP) is a rare, idiopathic, and benign skin condition that presents classically as erythematous to brown hyperkeratotic papules that can coalesce into plaques. Axillary GP was initially observed by Northcutt and colleagues and has since been described in various other areas of the body including other intertriginous and non-intertriginous sites. The term "granular parakeratosis" is now used to describe not only the skin condition, but also a distinctive histological reactive pattern on biopsy specimens that are either regarded as the disease itself, or merely as an incidental finding. Upon review of the current findings, opinions, and associations of this entity, we propose the reappraisal of GP as a reactive pattern, rather than a distinct entity.