Clinical and Dermoscopic Evaluation of Patients With Disorders of Hypopigmentation and Depigmentation

Hypopigmentary and depigmentary disorders frequently present with overlapping clinical features, often making diagnosis challenging. Dermoscopy serves as a valuable non-invasive tool that provides additional morphological information by revealing subsurface morphological patterns.

The aim of this study was to evaluate the clinical and dermoscopic features of various hypopigmentary and depigmentary disorders encountered in routine clinical practice.

A hospital-based observational cross-sectional study was conducted in 200 patients (aged 6-70 years, both genders) presenting with hypopigmentary and depigmentary disorders in a tertiary care dermatology outpatient department. All patients underwent detailed clinical examination, Wood's lamp examination, 10% potassium hydroxide (KOH) examination where indicated, and dermoscopic evaluation. Histopathological examination was performed in doubtful cases.

Among 200 patients, the majority belonged to the 11-20-year age group (33.5%). Vitiligo (36.5%), pityriasis versicolor (35.0%), and pityriasis alba (15.0%) were the most common disorders observed, whereas idiopathic guttate hypomelanosis, nevus depigmentosus, contact leukoderma, and leprosy were observed in a smaller number of patients. On Wood's lamp examination, vitiligo demonstrated bluish-white fluorescence, while pityriasis versicolor showed greenish-yellow to yellow fluorescence. KOH examination was positive in 81.4% of pityriasis versicolor cases with "spaghetti and meatballs" appearance. Vitiligo demonstrated absent pigment network (69.6%) and diffuse white glow (67.1%) on dermoscopy. Idiopathic guttate hypomelanosis showed margin patterns like amoeboid, feathery, and petaloid margins. Pityriasis versicolor showed brownish-white background (94.3%), faint pigment network (80.0%), and scaling accentuated in skin creases (72.9%). Pityriasis alba demonstrated ill-defined margins (93.3%) and a faint pigment network (73.3%). Leprosy lesions revealed yellowish-orange structureless areas (80.0%) with a distorted pigment network (60.0%).

Dermoscopy is a valuable adjunctive, non-invasive tool in differentiating clinically similar hypopigmentary and depigmentary disorders. Combined with Wood's lamp examination and KOH microscopy, it significantly improves diagnostic precision and may reduce the need for invasive investigations.