The prevalence of bullous pemphigoid in the US is reported as 6 to 10 cases per million, with a mean age of onset of 65 years.[2]Yeh SW, Ahmed B, Sami N, et al. Blistering disorders: diagnosis and treatment. Dermatol Ther. 2003;16:214-223.
http://www.ncbi.nlm.nih.gov/pubmed/14510878?tool=bestpractice.com
[5]Korman NJ. Bullous pemphigoid. The latest in diagnosis, prognosis, and therapy. Arch Dermatol. 1998;134:1137-1141.
http://www.ncbi.nlm.nih.gov/pubmed/9762028?tool=bestpractice.com
A disease primarily of the aged, with an average onset of age 80 to 89 years; there is concern that the incidence may rise with the increased numbers of people living to advanced age.[6]Jung M, Kippes W, Messer G, et al. Increased risk of bullous pemphigoid in male and very old patients: A population-based study on incidence. J Am Acad Dermatol. 1999;41:266-268.
http://www.ncbi.nlm.nih.gov/pubmed/10426901?tool=bestpractice.com
One study in the UK reported a 17% average yearly increase in the incidence of bullous pemphigoid, while a study in France reported a threefold increase in incidence over a period of 15 years.[7]Langan SM, Smeeth L, Hubbard R, et al. Bullous pemphigoid and pemphigus vulgaris - incidence and mortality in the UK: population based cohort study. BMJ. 2008;337:a180.
http://www.bmj.com/content/337/bmj.a180.full
http://www.ncbi.nlm.nih.gov/pubmed/18614511?tool=bestpractice.com
[8]Joly P, Baricault S, Sparsa A, et al. Incidence and mortality of bullous pemphigoid in France. J Invest Dermatol. 2012 Aug;132(8):1998-2004.
https://www.doi.org/10.1038/jid.2012.35
http://www.ncbi.nlm.nih.gov/pubmed/22418872?tool=bestpractice.com
Data on sex differences are conflicting.[6]Jung M, Kippes W, Messer G, et al. Increased risk of bullous pemphigoid in male and very old patients: A population-based study on incidence. J Am Acad Dermatol. 1999;41:266-268.
http://www.ncbi.nlm.nih.gov/pubmed/10426901?tool=bestpractice.com
[9]Ujiie H, Iwata H, Yamagami J, et al. Japanese guidelines for the management of pemphigoid (including epidermolysis bullosa acquisita). J Dermatol. 2019 Dec;46(12):1102-35.
https://www.doi.org/10.1111/1346-8138.15111
http://www.ncbi.nlm.nih.gov/pubmed/31646663?tool=bestpractice.com
[10]Kridin K. Subepidermal autoimmune bullous diseases: overview, epidemiology, and associations. Immunol Res. 2018 Feb;66(1):6-17.
http://www.ncbi.nlm.nih.gov/pubmed/29159697?tool=bestpractice.com
Some studies suggest the incidence may be higher in women until age 75 years, after which the incidence is higher in men.[10]Kridin K. Subepidermal autoimmune bullous diseases: overview, epidemiology, and associations. Immunol Res. 2018 Feb;66(1):6-17.
http://www.ncbi.nlm.nih.gov/pubmed/29159697?tool=bestpractice.com
Rarely, the disorder is seen in children.[11]Chimanovitch I, Hamm H, Georgi M, et al. Bullous pemphigoid of childhood: Autoantibodies target the same epitopes within the NC16A domain of BP180 as autoantibodies in bullous pemphigoid of adulthood. Arch Dermatol. 2000;136:527-532.
http://www.ncbi.nlm.nih.gov/pubmed/10768652?tool=bestpractice.com
[12]Fisler RE, Saeb M, Liang MG, et al. Childhood bullous pemphigoid: a clinicopathologic study and review of the literature. Am J Dermatopathol. 2003;25:183-189.
http://www.ncbi.nlm.nih.gov/pubmed/12775979?tool=bestpractice.com
In a 2-year retrospective study investigating all subepidermal immunobullous disorders seen at the National Skin Centre in Singapore, bullous pemphigoid accounted for 88% of all diagnoses, with predilection for ethnic Chinese and an average age of onset of 77 years.[13]Wong SN, Chua SH. Spectrum of subepidermal immunobullous disorders seen at the national skin centre, Singapore: a 2-year review. Br J Dermatol. 2002;147:476-480.
http://www.ncbi.nlm.nih.gov/pubmed/12207586?tool=bestpractice.com
North East Scotland appears to have a relatively high incidence of bullous pemphigoid (14 cases per million per year) when compared with incidence rates in continental Europe.[14]Gudi VS, White MI, Cruickshank N, et al. Annual incidence and mortality of bullous pemphigoid in the Grampian region of north-east Scotland. Br J Dermatol. 2005;153:424-427.
http://www.ncbi.nlm.nih.gov/pubmed/16086760?tool=bestpractice.com
The cause of this variability is not clear and may be related to racial predisposition to autoimmune skin disease, prevalence of predisposing HLA genotypes in the study population, or environmental influence.