Trichoscopy: The Best Auxiliary Tool in the Evaluation of Nevus Sebaceous

Nevus sebaceous (NS) presents as alopecia and yellowish discoloration during infantile stage. In adult stage, lesions become verrucous. Importantly, various appendageal tumors such as trichoblastoma, syringocystadenoma papilliferum and basal cell carcinoma develop during this stage. Hence it is very important to follow the course of NS for early detection of neoplasms. Trichoscopy, being in vivo diagnostic technique, can be utilized in this condition. as it demonstrates specific trichoscopic patterns. Patterns of NS on trichoscopy are evaluated.

Study was conducted in SN Medical College, Bagalkot. It is a case series study. Ten patients with NS were studied using polarised dermoscopy. All NS lesions were subjected to histopathology for confirmation of diagnosis. Correlation of histopathological changes and trichoscopic patterns was done. Data were tabulated in Microsoft excel sheet. The results are presented in proportions and percentages.

Total of 10 patients including 6males and 4 females were present in the study. The mean age was 20years. Two patients were with childhood stage and 8 patients were with adulthood stage of NS. Trichoscopy showed 'cobble stone pattern' in 20% and 'cerebriform pattern' in 80% of patients. Histopathological features showed numerous and hyperplastic sebaceous glands with primordial hair follicles which were consistent with NS in all the patients.

Trichoscopy helps in the diagnosis of NS with specific patterns. Yellowish globules in the cobblestone pattern and cerebriform patterns are specific to childhood and adult stages of NS respectively. Hence, trichoscopy is good, non-invasive diagnostic technique in NS. Authors strongly recommend regular trichoscopic examination of NS.