Degree of agreement between clinical diagnosis and dermoscopy in scabies

Abstract

Objective To determine the degree of agreement between clinical and dermoscopic diagnosis in patients of scabies. Methods A total of 210 patients with clinical suspicion of scabies were enrolled in the study. Patients were evaluated in a well lit room and those patients who met the definition of clinical diagnosis were recorded as having scabies. All patients were then subjected to dermoscopic examination of the suspicious areas e.g. interdigital clefts of hands, abdomen and groin. Findings were recorded on a predesigned proforma. Outcome variable was a positive or negative dermoscopic examination. Results Mean age of patients was 16±8.5 years with a range of 1 month to 87 yrs. Among 210 patients 116 (55.2%) were males and 94 (44.7 %) were females. Total of 112 patients (53.3%) were clinically diagnosed as scabies and 98 patients (46.7%) were not. Positive dermoscopic examination was recorded in 104 patients (49.5%) of whom 99 (95.2%) were also positive on clinical examination. Mite head was the most frequently visualized part, in 94.1% of the 104 cases. Negative dermoscopic examination was seen in 106 patients (50.5%) of whom 93 (87.7%) were also negative clinically. Hence 99 patients were true positives and 93 were true negatives.  Kappa test was used to assess the difference between the two (K=0.829, P < 0.05). Conclusion The results of this study suggest that there is almost a perfect agreement between the clinical diagnoses and dermoscopy for scabies (K=0.829).