Increased anthralin irritation response in vitiliginous skin

Area of Science:

• Dermatology
• Immunology
• Skin Physiology

Background:

• Vitiligo is a condition characterized by depigmented skin patches.
• Anthralin is a topical medication used to treat skin conditions like psoriasis and vitiligo.
• The skin's response to topical irritants can vary based on pigmentation.

Purpose of the Study:

• To investigate the irritation response to anthralin in vitiliginous skin compared to adjacent pigmented skin.
• To quantitatively assess the erythema induced by anthralin using objective measurements.
• To analyze the cellular infiltrate in response to anthralin in different skin types.

Main Methods:

• Chamber-testing technique applied to 17 vitiligo patients.
• Anthralin concentrations (0.1%-5%) applied to vitiliginous and pigmented skin for 24 hours.
• Visual assessment and chromometer readings for erythema evaluation; immunophenotypification of cellular infiltrates.

Main Results:

• Visual assessment suggested more intense erythema in pigmented skin, but chromometer readings revealed stronger erythema in vitiliginous skin.
• Inflammatory infiltrates in vitiliginous skin showed increased granulocytes and monocytes compared to normal skin.
• T-cell subsets, Langerhans cells, and mast cells percentages were similar in both skin types.

Conclusions:

• Objective measurements (chromometer) are more reliable than visual assessment for evaluating anthralin-induced erythema in vitiligo.
• Vitiliginous skin exhibits a heightened inflammatory response to anthralin, characterized by increased granulocytes and monocytes.
• Melanin's scavenging properties may contribute to reduced anthralin-induced radical species in pigmented skin.