P-21   CLINICAL SUBTYPES & DISEASE ASSOCIATIONS IN ALOPECIA AREATA

AJG McDonagh, SP MacDonald-Hull, AG Messenger, MP Birch, MJ Cork, R. Tazi-Ahnini Department of Dermatology & Division of Genomic Medicine, Royal Hallamshire Hospital, Sheffield UK.

In a series of 500 cases of alopecia areata (AA), we have analysed the interrelationships of disease subtype and associated clinical features including atopy, autoimmune disorders, nail involvement and family history of AA. There was no significant difference in the frequency of AA subtypes between men and women. Patchy AA (58%) formed the largest proportion followed by alopecia totalis (15%), universalis (21%) ophiasis (4%) and diffuse AA (2%). Nail involvement, atopy and associated autoimmune disorders were all commoner in cases of more severe disease (alopecia totalis, universalis & ophiasis) than in patchy AA. Diffuse AA was largely confined to the over 40 age group. The commonest associated autoimmune diseases were thyroid disorders (6%), vitiligo (2%) and rheumatoid disease (2%) but diabetes mellitus was particularly uncommon in our patients (0.8%). In keeping with autoimmunity in general, associated autoimmune diseases were commoner in women than men (P<0.01) and there was a significant subgroup of female patients with late onset patchy disease associated with other autoimmune disorders. Atopic individuals had an earlier median age at onset than non-atopic (27 vs 22 yrs, P<0.02) and the frequency of atopy was maximal in patients with ophiasiform disease (47%). Nail involvement, commonest in alopecia universalis (58% vs 8% in patchy AA), was strongly associated with alopecia of early onset (P<0.0001) and may be a marker of disease severity. A family history of AA was recorded in 28% of women and 20% of men overall. This rose to 35% in ophiasiform AA. Understanding relationships between the clinical manifestations in AA may assist in identifying genetic factors involved in the pathogenesis and our present findings support the separation of alopecia universalis from patchy AA in disease classification. To establish the validity of this classification, our results need confirmation in further large contemporary series.