Abstract
BACKGROUND: Contact immunotherapy using diphenylcyclopropenone (DPCP) is a recommended treatment for severe alopecia areata (AA); however, few clinical factors are known, and few standardized application methods affecting therapeutic efficacy have been devised. OBJECTIVE: To confirm the therapeutic response of DPCP immunotherapy in AA, first we analyze the factors influencing its outcome and patient satisfaction levels, after which we standardize the DPCP treatment method for better outcomes. METHODS: We utilized a nationwide questionnaire-based survey to assess patient satisfaction and undertook a medical record review involving 412 patients currently undergoing treatment for DPCP. RESULTS: The patients' mean age was 36.4 years, and 27% of the cases were diagnosed as AA in childhood. Treatment response was higher when DPCP was used to treat the entire scalp, including subclinical lesions, and longer treatment durations and longer intervals between treatments were associated with a better treatment response. Atopy (atopic dermatitis, allergic rhinitis and bronchial asthma), thyroid disorder, and extent of hair loss were all negatively correlated with the treatment response. However, there was no correlation between the treatment response and factors such as the age of onset, a family history of AA, nail changes, or AA duration, which are commonly known to be associated with a poor prognosis. CONCLUSION: DPCP immunotherapy is an effective treatment for AA, and the study demonstrated the factors affecting DPCP treatment response and patients' satisfaction and may contribute to standardizing the DPCP treatment method for better outcomes.