Dupilumab therapy rapidly improved alopecia areata associated with trichotillomania in an atopic dermatitis patient

Recent Advances in Understanding of the Etiopathogenesis, Diagnosis, and Management of Hair Loss Diseases

Hair-loss diseases comprise heterogenous conditions with respective pathophysiology and clinicopathological characteristics. Major breakthroughs in hair follicle biology and immunology have led to the elucidation of etiopathogenesis of non-scarring alopecia (e.g., alopecia areata, AA) and cicatricial alopecia (e.g., lichen planopilaris, LPP). High-throughput genetic analyses revealed molecular mechanism underlying the disease susceptibility of hair loss conditions, such as androgenetic alopecia (AGA) and female pattern hair loss (FPHL). Hair loss attracted public interest during the COVID-19 pandemic. The knowledge of hair loss diseases is robustly expanding and thus requires timely updates. In this review, the diagnostic and measurement methodologies applied to hair loss diseases are updated. Of note, novel criteria and classification/scoring systems published in the last decade are reviewed, highlighting their advantages over conventional ones. Emerging diagnostic techniques are itemized with clinical pearls enabling efficient utilization. Recent advances in understanding the etiopathogenesis and management for representative hair diseases, namely AGA, FPHL, AA, and major primary cicatricial alopecia, including LPP, are comprehensively summarized, focusing on causative factors, genetic predisposition, new disease entity, and novel therapeutic options. Lastly, the association between COVID-19 and hair loss is discussed to delineate telogen effluvium as the predominating pathomechanism accounting for this sequela.

Dupilumab in Inflammatory Skin Diseases: A Systematic Review

Dupilumab was first approved for the treatment of atopic dermatitis (AD) and blocks the signaling of interleukin (IL)-4 and -13. Several other chronic skin conditions share mechanistic overlaps with AD in their pathophysiology, i.e., are linked to type 2 inflammation. Most recently, dupilumab was approved by the U.S. Food and Drug Administration for prurigo nodularis (PN). Given its relatively good safety profile, effective off-label use of dupilumab has been reported for a multitude of dermatologic diseases and several clinical trials for dermatologic skin conditions are currently ongoing. We conducted a systematic review of applications of dupilumab in dermatology other than AD and PN by searching the databases PubMed/Medline, Scopus, Web of Science and Cochrane Library as well as the clinical trial registry ClinicalTrials.gov. We found several reports for effective treatment of bullous autoimmune diseases, eczema, prurigo, alopecia areata, chronic spontaneous urticaria, Netherton syndrome and a variety of other chronic inflammatory skin diseases.

Short communication: Comments on hair disorders associated with dupilumab based on VigiBase

Background

Dupilumab is a human antibody that blocks the signaling of both interleukin-4 and interleukin-13 receptors. It has been approved for the treatment of moderate-to-severe atopic dermatitis. However, several case reports have reported conflicting effects of dupilumab on alopecia.

Objectives

This study aimed to examine dupilumab-related hair disorders using the large real-world database, VigiBase.

Methods

All individual case safety reports associated with dupilumab in the Uppsala Monitoring Center VigiBase until December 29, 2019, were analyzed. Hair disorder-related terms were defined in High Level Terms with “alopecias,” “pilar disorders NEC (not elsewhere classified),” and “hypertrichoses,” using the Medical Dictionary for Regulatory Activities Hierarchy. Hair disorder reports associated with dupilumab and other biologics that inhibit the Th2 axis (omalizumab, mepolizumab, reslizumab, and benralizumab) were analyzed to determine their association with hair disorders. Disproportionality analysis was performed based on the proportional reporting ratio, reporting odds ratio, and information components.

Results

Among the 20,548 total dupilumab adverse event (AE) reports, hair disorders were reported in 462 dupilumab cases (2.2%), most of which reported hair loss, and only eight cases reported an increase in hair growth. The paradoxical trend in hair loss and growth after dupilumab use was confirmed using a disproportionality analysis. Among the other investigated biologics on Th2 immunity, only omalizumab was associated with hair loss. Additionally, hair disorders after dupilumab treatment were more frequently reported in women than in men. The proportion of hair disorder cases was high in Europe, accounting for 20.8% of hair disorder reports, whereas only 9.7% of all dupilumab-related AEs were reported in Europe. In conclusion, our analysis using a large real-world database confirmed that dupilumab is associated with hair disorders.

Association analysis of non-synonymous polymorphisms of interleukin-4 receptor-α and interleukin-13 genes in canine atopic dermatitis

Interleukin-4 (IL4) and interleukin-13 (IL13) are involved in the initial response of T helper 2 lymphocytes through the activation of the IL4 receptor alpha (IL4RA), which is a common receptor chain for these cytokines. In humans, several single-nucleotide polymorphisms (SNPs) identified in the IL4R and in interleukin coding genes were associated with atopic disorders. However, the association between canine IL4R polymorphisms and atopic disorders has not been investigated yet. This study aimed to determine the associations between four non-synonymous SNPs and canine atopic dermatitis (CAD) in shiba inu and miniature dachshund populations. Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis were used to genotype four polymorphisms of canine IL4R and IL13 in 34 shiba inu and 19 miniature dachshund patients with CAD, as well as 29 shiba inu and 39 miniature dachshund patients without the condition. Results from miniature dachshunds revealed a potential association between the presence of minor A allele rs24378020 and CAD (odds ratio, 0.10; 95% confidence interval, 0.01–0.85; P_original=0.0062). This CAD resistance allele led to an amino acid substitution (Arg688Cys) that could impair IL4 and IL13 signaling. In shiba inu patients, rs24378020 was fixed by homozygosity of the major G allele. No association was found between the remaining three evaluated SNPs and CAD. Nevertheless, the study suggests that the IL4R Cys688 variant reduces the risk of CAD in miniature dachshunds.