Clinico-Pathological Concordance Rate of Scalp Lesions Showing Alopecia

BACKGROUND: Some alopecic diseases can be diagnosed by detailed history taking and physical examination, but in many cases, biopsy must be performed to make a definite diagnosis. AIMS AND OBJECTIVES: This study aimed to evaluate the clinico-pathological concordance of scalp lesions showing alopecia. MATERIALS AND METHODS: We retrospectively reviewed the electronic medical records and biopsy slides of patients who underwent biopsy for evaluating scalp lesions showing alopecia. Based on the definitions of clinico-pathological concordances, scalp alopecic disease was evaluated. RESULTS: A total of 121 patients were enrolled in the study. A total of 203 clinical differential diagnoses were made before performing a biopsy. Thirty-one patients showed full concordance, and 58 patients showed partial concordance; thus overall concordance was shown in 89 patients (73.55%). Folliculitis decalvans and alopecia areata showed a higher full concordance rate than average (P < 0.05), whereas dissecting folliculitis showed a lower overall concordance rate than average, and folliculitis decalvans showed a higher overall concordance rate than average (P < 0.05). The overall concordance rate of alopecia areata was 100% (P = 0.061). CONCLUSION: In diagnosing folliculitis decalvans and alopecia areata, which showed high full and overall concordance, performing a biopsy to make a definite diagnosis is not always necessary, especially when patients show typical clinical features. Dissecting folliculitis, which showed low overall concordance, was less likely to be suspected as a clinical differential diagnosis, making it difficult to distinguish based on clinical findings alone. Therefore, when it is suspected, a detailed evaluation including a biopsy is recommended.