Acta Demato-Venereologica 98-2CompleteContent | Page 11

CLINICAL REPORT

195 Advances in dermatology and venereology ActaDV Acta Dermato-Venereologica ActaDV

Diagnostic Delay in Dermatitis Herpetiformis in a High-prevalence Area
Eriika MANSIKKA 1 , 2 , Teea T . SALMI 1 , 2 , Katri KAUKINEN 2 , 3 , Pekka COLLIN 4 , Heini HUHTALA 5 , Timo REUNALA 1 , 2 and Kaisa
HERVONEN 1 , 2 1
Department of Dermatology , 3 Department of Internal Medicine , 4 Department of Gastroenterology and Alimentary Tract Surgery , Tampere University Hospital , 2 Faculty of Medicine and Life Sciences , and 5 Faculty of Social Sciences , University of Tampere , Tampere , Finland
Dermatitis herpetiformis ( DH ) is an extra-intestinal manifestation of coeliac disease . The highest currently reported prevalence of DH is in Finland , but knowledge of diagnostic delay is limited . This study investigated the duration of rash prior to diagnosis in 446 patients with DH , analysing the results in 3 periods of 15 years . The diagnosis was considered delayed when the duration of rash before diagnosis was 2 years or longer . Factors associated with delayed diagnosis were analysed . Within the 45 years , the median duration of rash before diagnosis decreased significantly , from 12.0 to 8.0 months ( p = 0.002 ) and the occurrence of a delayed diagnosis decreased from 47 % to 25 % ( p = 0.002 ). Female sex , the presence of villous atrophy , and a diagnosis of DH before the year 2000 were significantly associated with delayed diagnosis . In conclusion , the present study showed that one-quarter of patients currently have a diagnostic delay of 2 years or more , which is far from ideal .
Key words : dermatitis herpetiformis ; coeliac disease ; diagnostic delay ; gluten-free diet ; dapsone .
Accepted Oct 16 , 2017 ; Epub ahead of print Oct 19 , 2017 Acta Derm Venereol 2018 ; 98 : 195 – 199 .
Corr : Kaisa Hervonen , Department of Dermatology , Tampere University Hospital , PO Box 2000 , FIN-33521 Tampere , Finland . E-mail : kaisa . hervonen @ staff . uta . fi

Dermatitis herpetiformis ( DH ) is a cutaneous manifestation of coeliac disease presenting as an itchy polymorphic blistering rash on the elbows , knees , buttocks and scalp ( 1 ). Diagnosis of DH is based on the presence of typical skin symptoms and the demonstration of IgA in the papillary dermis during direct immunofluorescence examination ( 2 ). Although 75 % of patients with DH have small bowel mucosal villous atrophy at diagnosis , only a minority have marked gastro intestinal symptoms ( 3 , 4 ). The treatment of DH is a lifelong gluten-free diet ( GFD ), similar to treatment of coeliac disease ( 4 , 5 ). A GFD results in healing of the enteropathy and the rash , but the rash alleviates slowly and additional treatment with dapsone ( 4,4 ’ -diaminodiphenylsulfone) is frequently needed at the start of dietary treatment ( 6 , 7 ).

DH is considered relatively uncommon , having the highest reported prevalence of 75.3 per 100,000 people in
Finland and a lower prevalence in UK and the USA ( 8 – 10 ). In contrast to the established increase in the incidence of coeliac disease , the incidence of DH decreased in both Finland and UK during the 1990s ( 8 , 9 ). DH constitutes a diagnostic challenge to general practitioners and other non-dermatologists , and can easily be misdiagnosed as other itchy or blistering skin diseases ( 11 , 12 ). Early diagnosis is warranted in DH , since ongoing symptoms reduce quality of life , and undiagnosed DH predisposes to complications , such as lymphoma and low bone mineral density ( 13 – 15 ).
For coeliac disease , the median time from onset of gastro intestinal symptoms to diagnosis in Finland is currently 3 years ( 16 ). Fortunately , diagnostic delay has decreased over the past decades in Finland , other European countries , and the USA ( 17 – 20 ). However , up-to-date knowledge about diagnostic delay in DH is lacking . The aim of this study was to investigate the changes in the diagnostic delay in DH and to analyse possible factors associated with delayed diagnosis . Our prospectively collected large DH cohort enabled us to perform delay analyses for 3 periods of 15 years .
PATIENTS AND METHODS
All patients suspected of having DH in the Tampere region , Finland , are referred by private dermatologists and general practitioners working in healthcare centres to the Department of Dermatology , Tampere University Hospital , for confirmation of DH diagnosis . Clinical suspicion of DH is an adequate reason for referral regardless of coeliac autoantibody result , and the referral policy for DH has remained the same for the years of the present study . In Tampere University Hospital , diagnosis of DH is based on the detection of typical clinical symptoms and the presence of granular IgA deposits in the papillary dermis ( 2 ), and this diagnostic procedure has remained unchanged during the study period . All patients are treated at a special DH clinic , where they are advised to adhere to a lifelong GFD .
Our DH cohort consists of 512 patients who had been diagnosed and treated at the DH clinic between 1970 and 2014 . A total of 446 patients were included for further analysis . Of the 66 patients excluded , 10 did not have IgA deposits in the skin , 21 had died over 20 years previously and their data was not available , and 35 had a previous diagnosis of coeliac disease . Data on the duration of the rash before diagnosis were collected from medical records held at Tampere University Hospital . The diagnosis was considered delayed when the duration of the rash before diagnosis was 2 years or more . The definition for delayed diagnosis was based on a previous study performed in our hospital district ( 21 ) and
This is an open access article under the CC BY-NC license . www . medicaljournals . se / acta Journal Compilation © 2018 Acta Dermato-Venereologica . doi : 10.2340 / 00015555-2818 Acta Derm Venereol 2018 ; 98 : 195 – 199