Although PLE is one of the most common photodermatoses, data for prevalence and incidence are scarce, due to only a small percentage of affected individuals consulting a physician when symptoms appear. In one meta-analysis, the prevalence of PLE ranged from 0.13% to 21.4% with an estimated pooled prevalence of 10% among the general population. There is a higher prevalence with increasing distance from the equator and the lowest prevalence is observed in China.[14]Burfield L, Rutter KJ, Thompson B, et al. Systematic review of the prevalence and incidence of the photodermatoses with meta-analysis of the prevalence of polymorphic light eruption. J Eur Acad Dermatol Venereol. 2023 Mar;37(3):511-20.
https://onlinelibrary.wiley.com/doi/10.1111/jdv.18772
http://www.ncbi.nlm.nih.gov/pubmed/36433668?tool=bestpractice.com
In a large European study of 6895 patients the overall prevalence in Europe is reported at 18.2%. It is particularly higher in Northern Europe compared with Southern Europe, potentially due to a higher prevalence of lighter skin types, higher photosensitivity, or possibly a genetic predisposition.[15]Millard TP, Bataille V, Snieder H, et al. The heritability of polymorphic light eruption. J Invest Dermatol. 2000 Sep;115(3):467-70.
https://www.jidonline.org/article/S0022-202X(15)40996-0/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/10951285?tool=bestpractice.com
[16]McGregor JM, Grabczynska S, Vaughan R, et al. Genetic modeling of abnormal photosensitivity in families with polymorphic light eruption and actinic prurigo. J Invest Dermatol. 2000 Sep;115(3):471-6.
https://www.jidonline.org/article/S0022-202X(15)40997-2/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/10951286?tool=bestpractice.com
[17]Ros AM, Wennersten G. Current aspects of polymorphous light eruptions in Sweden. Photodermatology. 1986 Oct;3(5):298-302.
http://www.ncbi.nlm.nih.gov/pubmed/3547354?tool=bestpractice.com
[18]Rhodes LE, Bock M, Janssens AS, et al. Polymorphic light eruption occurs in 18% of Europeans and does not show higher prevalence with increasing latitude: multicenter survey of 6,895 individuals residing from the Mediterranean to Scandinavia. J Invest Dermatol. 2010 Feb;130(2):626-8.
https://www.jidonline.org/article/S0022-202X(15)34705-9/fulltext
In Australia there appears to be a high incidence of PLE in the white population, similar to that found in Northern Europe.[19]Pao C, Norris PG, Corbett M, et al. Polymorphic light eruption: prevalence in Australia and England. Br J Dermatol. 1994 Jan;130(1):62-4.
http://www.ncbi.nlm.nih.gov/pubmed/8305319?tool=bestpractice.com
Women appear to be more commonly affected (2:1 female-to-male ratio), although it is still unclear whether this is due to reporting bias or a genetic predisposition.[1]Holzle E, Plewig G, von Kries R, et al. Polymorphous light eruption. J Invest Dermatol. 1987;88(3 Suppl):32s-8.
http://www.ncbi.nlm.nih.gov/pubmed/3819473?tool=bestpractice.com
[9]Berg M. Epidemiological studies of the influence of sunlight on the skin. Photodermatology. 1989 Apr;6(2):80-4.
http://www.ncbi.nlm.nih.gov/pubmed/2748434?tool=bestpractice.com
[15]Millard TP, Bataille V, Snieder H, et al. The heritability of polymorphic light eruption. J Invest Dermatol. 2000 Sep;115(3):467-70.
https://www.jidonline.org/article/S0022-202X(15)40996-0/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/10951285?tool=bestpractice.com
[16]McGregor JM, Grabczynska S, Vaughan R, et al. Genetic modeling of abnormal photosensitivity in families with polymorphic light eruption and actinic prurigo. J Invest Dermatol. 2000 Sep;115(3):471-6.
https://www.jidonline.org/article/S0022-202X(15)40997-2/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/10951286?tool=bestpractice.com
[20]Aubin F. Why is polymorphous light eruption so common in young women? Arch Dermatol Res. 2004 Oct;296(5):240-1.
http://www.ncbi.nlm.nih.gov/pubmed/15349790?tool=bestpractice.com
PLE tends to recur over many years and all age groups are affected, however it is more common in adolescents and young adults.[1]Holzle E, Plewig G, von Kries R, et al. Polymorphous light eruption. J Invest Dermatol. 1987;88(3 Suppl):32s-8.
http://www.ncbi.nlm.nih.gov/pubmed/3819473?tool=bestpractice.com
[8]Guarrera M, Micalizzi C, Rebora A. Heterogeneity of polymorphous light eruption: a study of 105 patients. Arch Dermatol. 1993 Aug;129(8):1060-1.
http://www.ncbi.nlm.nih.gov/pubmed/8352615?tool=bestpractice.com
While the condition seems to appear more frequently in fair skin types, some studies also report a high incidence in darker skin types, including African Americans.[21]Fotiades J, Soter NA, Lim HW. Results of evaluation of 203 patients for photosensitivity in a 7.3-year period. J Am Acad Dermatol. 1995 Oct;33(4):597-602.
http://www.ncbi.nlm.nih.gov/pubmed/7673491?tool=bestpractice.com
[22]Kerr HA, Lim HW. Photodermatoses in African Americans: a retrospective analysis of 135 patients over a 7-year period. J Am Acad Dermatol. 2007 Oct;57(4):638-43.
http://www.ncbi.nlm.nih.gov/pubmed/17630044?tool=bestpractice.com
[23]Nakamura M, Henderson M, Jacobsen G, et al. Comparison of photodermatoses in African-Americans and Caucasians: a follow-up study. Photodermatol Photoimmunol Photomed. 2014 Oct;30(5):231-6.
http://www.ncbi.nlm.nih.gov/pubmed/24118606?tool=bestpractice.com