LAUSR

Dermatitis herpetiformis (Duhring’s disease): a therapeutic challenge Dear Editor, I read with great interest in the International Journal of Dermatology a report on dermatitis herpetiformis (DH) by Bevans and Sami. The authors reported a successful trial of dapsone/sulfasalazine combination in the treatment of dapsone-refractory DH patients. Dermatitis herpetiformis is an autoimmune blistering condition seen in the context of celiac disease. Due to its anti-inflammatory and immunomodulatory effects, dapsone is considered the drug of first choice in neutrophil-rich autoimmune bullous diseases such as linear IgA dermatosis and DH. Individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency are more sensitive to developing hemolytic anemia after exposure to hemolytic stressors including dapsone. Meinzer et al. reported a female patient with linear IgA bullous dermatosis, another subepidermal neutrophil-predominant blistering dermatosis, who developed symptoms such as fatigue and increasing dyspnea on exertion while on dapsone. Workup revealed the presence of interstitial lung disease in the form of esinophilic pneumonia. Dapsoneinduced esinophilic pneuomonia, albeit rare, may be misinterpreted in a DH asthmatic patient as in the first patient with coassociated asthma and bronchitis. The other patient reported by the authors was a female patient with a history of hypertension and Raynaud’s disease. The clinical value of the coassociated Raynaud’s disease should be addressed, whether its presence was coincidental or secondary to underlying disease. Recently, Bogn ar et al. reported a high prevalence of isolated cryofibrinogenemia (CFE) among 88 DH patients. The highest rate of CFE was detected in the group of untreated patients; it decreased under gluten-free diet (GFD) and was not detected in patients under GFD and dapsone treatment. CFE was more prevalent than cryoglobulinemia among the studied patients. CFE may exist asymptomatically, but skin findings such as acral purpuras and Raynaud phenomenon may develop. It is appropriate in any patient with DH presented with coassociated signs as Raynaud disease/phenomenon to be screened for possible CFE. In their study, G€ or€ og et al. observed that the fibrinolytic potential was impaired in the plasma of untreated DH patients, whereas dapsone corrected the fibrinolytic defect. These data add a new aspect to the long-known beneficial, symptomatic effect of dapsone in active DH, particularly those associated with abnormal coagulation profiles. Gasparyan et al. reported that colchicine, in addition to its antineutrophilic effect, also has antithrombotic and antifibrotic effects, hence considered a cardioprotective agent. It seems to be suitable for elderly people with cardiovascular risks such as hypertension, as in the case of the second patient. A trial of colchicine has been suggested when conventional therapy with dapsone is contraindicated/ineffective or when a gluten-free diet cannot be employed as reported by Silvers et al. In patients with potential risk of dapsone adverse effects, particularly the cardiac patients, colchicine may be a good alternative or adjuvant therapy. Treatment of DH may be a therapeutic challenge. Although dapsone/sulfasalazine combination proved to be effective in DH, other antineutrophilic drugs with excellent safety profile, such as colchicine, should be tried first. Dapsone is a cornerstone in management of DH. Dapsone may protect against signs of CFE such as Raynaud’s disease; however, it should be withheld and administration of systemic steroids started in the event of unexplained fatigue and dyspnea on exertion. Again, I would like to thank the authors for this opportunity to discuss this interesting successful trial.