UV-Trichoscopic Red Fluorescence in Alopecia Areata

Evaluation of UV-Trichoscopic Red Fluorescence Intensity in Relation to Trichoscopic Findings and Response to Intralesional Corticosteroid Treatment in Limited Plaque-Type Alopecia Areata

The goal of this observational study is to learn whether red fluorescence seen with ultraviolet (UV) trichoscopy is related to disease findings and treatment response in adults with limited plaque-type alopecia areata. Trichoscopy is a close-up imaging method used to examine the hair and scalp. The study will investigate whether the amount of red fluorescence at the beginning of the study is related to how soon hair starts to grow back, how much hair regrows, and how trichoscopic findings change during follow-up. Participants for whom intralesional corticosteroid treatment has been planned as part of their regular medical care will have standard trichoscopic and UV-trichoscopic images taken of the affected scalp area. They will be followed at weeks 4, 8, and 12, when hair regrowth and changes in scalp and hair findings will be evaluated. Researchers will measure red fluorescence in the images and examine whether it is related to treatment response over time.

This is a prospective observational cohort study involving adults with limited plaque-type alopecia areata who are receiving intralesional corticosteroid treatment as part of routine clinical care. Participation in the study does not determine whether a patient receives intralesional corticosteroid treatment.

At baseline, the affected scalp area will be evaluated using conventional polarized trichoscopy and UV-trichoscopy. Follow-up assessments will be performed at weeks 4, 8, and 12 using the same imaging approach. Trichoscopic findings of interest will include yellow dots, black dots, exclamation mark hairs, and broken hairs.

UV-trichoscopic red fluorescence will be assessed quantitatively by measuring red-channel intensity on standardized digital images. Imaging and image analysis procedures will be performed using a standardized acquisition protocol to improve comparability between visits.

Treatment response will be evaluated according to the appearance and extent of visible hair regrowth and the change in trichoscopic activity findings during follow-up. The main analysis will examine whether baseline red fluorescence intensity is associated with the timing and magnitude of response to intralesional corticosteroid treatment. Associations between red fluorescence intensity and baseline trichoscopic findings, as well as changes in fluorescence intensity and trichoscopic findings over time, will also be evaluated.

Inclusion Criteria:

• Age 18 years or older
• Limited plaque-type alopecia areata of the scalp
• Active hair loss
• Symptom onset within the previous 6 months
• No topical, intramuscular, or oral treatment for alopecia areata within the previous 1 month
• No intralesional corticosteroid treatment within the previous 6 weeks
• Provision of informed consent

Exclusion Criteria:

• Beard alopecia areata
• Very extensive alopecia areata or multiple large plaques
• Tinea capitis or active infection
• Current phototherapy
• Systemic immunosuppressive treatment within the washout period specified in the study protocol
• Pregnancy or breastfeeding
• Contraindication to UV imaging