Epidemiology and clinical features of psoriasis in hard-to-treat body locations: A Chinese nationwide population-based study

Abstract

Background Having psoriasis in hard-to-treat areas, such as the scalp, face, palms, soles, nails, and genitals, can suffer from a reduced quality of life. This study was designed to investigate the prevalence and risk factors of hard-to-treat body locations of psoriasis, and to describe patients’ clinical and demographic characteristics, and quality of life impacts. Methods We conducted a multicenter observational epidemiological study involving over 1000 hospitals in China, enrolling a total of 7032 psoriasis patients. Groups were compared to patients without involvement of hard-to-treat areas. Results The most frequently affected hard-to-treat area was the scalp (60.01%), followed by the face (22.47%), nails (18.87%), palms or soles (18.23%), genitals or vulvas (12.00%), respectively. Among all patients, 70.71%, 36.65%, 16.30%, 6.48% and 1.45% of patients had involvement of ≥ 1, ≥2, ≥ 3, ≥4 or ≥ 5 hard-to-treat areas. There was a male predominance among patients with involvement of at least one difficult-to-treat area(P < 0.001). The smoking rate, BMI (body mass index) and psoriasis family history in patients with at least one hard-to-treat area involvement were significantly higher than those in patients without hard-to-treat area involvement (P < 0.001), especially among patients with nail involvement. With regards to current DLQI (dermatology life quality index), satisfactory rate, and current BSA (body surface area), these findings were all significantly different (P < 0.001) when compared to patients without involvement of a hard-to-treat area. Even in mild to moderate patients (BSA < 10), the quality of life and satisfaction rate were significantly affected(P < 0.001) when hard-to-treat areas were involved. Conclusion Psoriasis commonly affects hard-to-treat locations, even in patients with mild to moderate disease (BSA < 10). For some of these areas, DLQI, satisfaction rate is impaired. Smoking, overweight and obesity, and a family history of psoriasis could be risk factors for the occurrence of hard-to-treat area involvement in psoriasis patients.