Poor agreement between self-reported and dermatologists' diagnoses for five common dermatoses.

Area of Science:

• Epidemiology
• Dermatology
• Public Health

Background:

• Limited epidemiological data exists for chronic dermatoses in France, with existing studies often using biased samples.
• Self-reported disease prevalence is questionable due to potential under- or overestimation compared to actual diagnoses.

Purpose of the Study:

• To assess agreement between self-reported and dermatologist diagnoses for five chronic skin conditions: acne, eczema, fungal infections, psoriasis, and seborrheic dermatitis.
• To identify factors influencing patients' awareness and knowledge of their dermatological diagnoses.

Main Methods:

• A cross-sectional study involving 4,622 adults examined by dermatologists across 134 centers in France.
• Utilized self-administered questionnaires for patient self-reports and standardized forms for dermatologist diagnoses.
• Analyzed diagnostic agreement using the kappa index and explored factors associated with diagnosis knowledge via logistic regression.

Main Results:

• Self-reported prevalence was significantly lower than dermatologist-diagnosed prevalence for four out of five conditions (except eczema), with underestimations ranging from 23% to 35%.
• Agreement between self-reported and dermatologist diagnoses was low to moderate.
• Diagnosis knowledge was negatively associated with age (over 54) and positively associated with treatment and social life impairment.

Conclusions:

• A significant discrepancy exists between self-reported and dermatologist diagnoses for common chronic skin diseases.
• Self-reporting substantially underestimates the prevalence of several prevalent dermatoses, indicating limitations for epidemiological use.