Erythropoietic protoporphyria in the U.K.: clinical features and effect on quality of life.
BACKGROUND
Erythropoietic protoporphyria (EPP) is a rare inherited photodermatosis that causes lifelong painful photosensitivity. Neither its full clinical spectrum nor its impact on quality of life (QoL) has been investigated in a large cohort of patients.


OBJECTIVE
To document the clinical features of EPP and its impact on QoL in a high proportion of all patients with EPP resident in the U.K.


METHODS
Patients with EPP were identified from U.K. clinical databases and assessed by the same clinical investigator over a 7-month period using a standardized proforma and validated adult (Dermatology Life Quality Index, DLQI) and children's (Children's Dermatology Life Quality Index, CDLQI) QoL questionnaires.


RESULTS
Three hundred and eighty-nine living patients with EPP were identified, of whom 223 [114 females, 109 males; median age 34 years (range: 5-87), from 193 families] were investigated. Total erythrocyte porphyrin (TEP) was higher in males (median: 25.3 micromol L1) than females (median: 19.3 micromol L1). The median ages at onset and diagnosis were 1 and 12 years, respectively. Median times for onset of symptoms after sun exposure, onset of signs (oedema, erythema) and resolution of symptoms were 20 min, 6 h and 3 days, respectively. Most patients reported absence of protection by glass (92%), priming (85%), exacerbation by wind (68%), no family history of photosensitivity (56%), no symptoms during winter (56%) and had chronic skin lesions (79%). Symptoms changed little with age but improved during pregnancy in 47% of gravid women. Most patients used protective clothing and a sunscreen; 28% were taking beta-carotene and a further 56% had taken it; 29% were not under regular medical care. Two patients (1%) had liver failure and 8% reported gallstone disease. QoL was markedly impaired, with scores similar to those in severe dermatological disease (mean DLQI score 14.0, n = 176; mean CDLQI score 12.8, n = 44), indicating a large effect on patients' lives. DLQI scores correlated weakly with TEP (rs = 0.228; P = 0.002) and time to onset of symptoms (rs = -0.233; P = 0.002) but not with age at onset.


CONCLUSIONS
EPP is a persistent, severely painful, socially disabling disease with a marked impact on QoL. Its diagnosis is often overlooked. None of TEP, age at onset nor time to onset of symptoms is a useful predictor of impaired QoL in individual patients.
Holme
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SA
Department of Dermatology, Cardiff University, Heath Park, Cardiff CF14 4XN, UK. alex.holme@faht.scot.nhs.uk
Anstey
A V
AV
Finlay
A Y
AY
Elder
G H
GH
Badminton
M N
MN
D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D008297:Male; D008875:Middle Aged; D010787:Photosensitivity Disorders / Q000150:complications; D011166:Porphyrins / Q000097:blood; D046351:Protoporphyria, Erythropoietic / Q000097:blood / Q000209:etiology / Q000534:rehabilitation* / Q000628:therapy; D011788:Quality of Life; D012720:Severity of Illness Index; D012959:Socioeconomic Factors; D013472:Sunlight / Q000009:adverse effects
D011166:Porphyrins