Usage of Dermoscopy as an Effective Diagnostic Tool in Pityriasis Alba: A Prospective Observational Study Among Children in a Suburban Hospital in South India

Background: Hypopigmented patches in patients with skin of color are usually a cause of concern. Pityriasis alba is a common skin condition that causes visible patches of hypopigmentation in children and adolescents. In addition to the cosmetic impairment, parents are concerned about the diagnosis of vitiligo and leprosy which also cause hypopigmented patches and have negative social implications. Dermoscopy is a useful diagnostic aid that is acquiring prominence in diagnosing a variety of skin diseases. Few studies exist that validate the use of dermoscopy as an effective tool in the diagnosis of Pityriasis alba. Objective: To evaluate the effectiveness of dermoscopy by correlating the clinical features of Pityriasis alba with dermoscopic images. Methods: Hypopigmented patches in 16 patients that were clinically diagnosed as Pityriasis alba were examined with a DermLite DL200 Hybrid dermoscope (Dermlite, CA, USA). All the dermoscopic images were photographically recorded and the findings were noted and correlated with the clinical stages of the disease. Results: Out of the 40 patches examined in 16 patients, dermoscopic images of white structureless spots, scaling, indistinct borders and normally pigmented hairs were consistently present in all the patches to propose these as the four dermoscopic criteria for the diagnosis of Pityriasis alba. Areas of light brown pigmentation, 17 (42.5%), erythema, 3 (7.5%), and faint pigmented network,11 (27.5%) were the other features noted in some of the patches. Conclusion: In an ethnic South Indian population where the skin color is predominantly brown, hypopigmented patches are visibly obvious and concerning. Pityriasis alba, Pityriasis versicolor, Vitiligo, Nevus depigmentosus, and Leprosy are the five common conditions seen among children of which Pityriasis alba is the most prevalent. Offering the right diagnosis is essential for the correct management as well as excluding more serious conditions such as leprosy and vitiligo. In this study, Dermoscopy provided a valuable diagnostic aid in achieving this objective.