Title : Dermatitis herpetiformis: Recent trends in incidence and management
Abstract:
Dermatitis herpetiformis (DH), the cutaneous manifestation of celiac disease (CD), is a pruritic gluten-dependent bullous disorder. In recent years, there has been a notable decline in DH incidence rates despite rising CD diagnoses. During this time, the gluten-free diet (GFD) has been met with increasing popularity and the market share of gluten-free foods has substantially grown. This simultaneous decrease in gluten consumption emphasizes the potential influence this may have had on DH incidence, prompting this review. This review synthesizes recent epidemiologic shifts, molecular insights and therapeutic advances for DH.
An extensive review of the literature revealed a decrease in incidence rates and an increase in the mean age at DH diagnosis. In Northern Europe, DH incidence has fallen 40- 60%, with Finland dropping from 5.2 to 2.1 per 100,000 per year and Sweden from 3.1 to 1.4 per 100,000 per year, yet the diagnostic age has risen to 54 years. This can be attributed to several factors. For one, decreased gluten consumption in both susceptible and healthy populations can explain for the downward trends in DH incidence. Overall, population gluten intake has decreased 52%, and gluten-free diet (GFD) adherence in DH exceeds 95% (increased). Additionally, recent diagnostic improvements have led to earlier recognition of underlying CD and, hence, a smaller pool of patients with neglected subclinical CD that can potentially progress to DH.
Dapsone remains the first-line pharmacologic therapy, but JAK inhibitors and dupilumab now achieve remission in refractory cases, with IL-36/IL-17 blockade being tested. To date, only a few isolated case reports and limited clinical research exists detailing these targeted therapies. Monoclonal antibodies like rituximab has been proven to be effective in treating DH, with recent instances citing success with dupilumab. Additionally, three isolated cases published within the past five years have reported the efficacy of JAK inhibitors, including tofacitinib, baricitinib and, most recently, novel use of upadacitinib for DH. Research exploring the cytokines involved in DH pathogenesis revealed overexpression of IL-7, IL-31 and IL-36, laying the groundwork for new potential therapies. Biologics targeting these agents serve as a promising candidate for DH treatment.
It’s evident that there has been a decline in DH incidence amongst recent decades, all while diagnostics have advanced and the GFD has experienced a surge in popularity. It can be postulated that this increased awareness of underlying CD and a lower lifetime gluten load has contributed to these trends. Focusing on this key epidemiological data, this emphasizes the treatable and preventable nature of this skin condition. This underscores the need for attentive, routine monitoring in those with gluten sensitivities and early implementation of the GFD. Regular follow ups and diligent screening efforts are key to maintaining this decline in DH incidence. DH has been found to coexist with several autoimmune comorbidities, stressing the necessity of screening for DH in those with preexisting auto-immunities. This review concludes with follow-up guidelines and screening recommendations for those at risk of developing DH or an eventual complication.
