Isolated itching of external auditory canal: clinicopathological study with immunohistochemical determination of antimicrobial peptides.

OBJECTIVE: This study aimed to demonstrate the histological and immunohistological features of skin biopsy specimens from patients complaining of isolated itching of the external auditory canal. MATERIALS AND METHODS: A prospective, case-control study was performed of 24 patients undergoing evaluation for contact dermatitis of the external auditory canal, and 24 controls. Skin biopsies were examined histologically by a single, blinded dermatopathologist, using light microscopy, to determine histopathological characteristics. The immunohistological presence of the antimicrobial peptides human β-defensin-3 and LL-37 cathelicidin was also assessed. Findings for patients and controls were compared. RESULTS: There was a statistically significant difference in the degree of inflammation, comparing patients and controls (p < 0.05). There was no significant difference in the presence of spongiotic changes, comparing patients and controls (p > 0.05). Furthermore, the patients' skin biopsies did not show pronounced expression of human β-defensin-3 or LL-37 cathelicidin. CONCLUSION: Histological and immunohistological examination of skin biopsies from cases of isolated itching of the external auditory canal did not support a diagnosis of dermatitis.