Correlation between cytological characteristics of the nasal epithelium and the menstrual cycle.

BACKGROUND There has been considerable controversy concerning the effect of hormones on the nasal epithelium and, in particular, their association with the female reproductive state. OBJECTIVE To investigate the relationship between cytological characteristics of the nasal epithelium and phase of the menstrual cycle. Design and Subjects Nasal smears were obtained from 15 women during the menstrual, follicular, and luteal phases, and the abundance of different cell types at each phase was compared with the abundance of equivalent cell types in vaginal smears during the follicular and luteal phases; the nasal smears were also compared with nasal smears from 20 postmenopausal women and 20 prepubertal girls. Epithelial cell counts were conducted by an observer blind to the origin of the samples. RESULTS A significant correlation was found between the cytological characteristics of the nasal and vaginal smears and stage of the cycle, with cornified cells predominating during the follicular phase (median, 54%; range, 24%-65%) and rounded or spindle-shaped epithelial cells predominating during the luteal phase (median, 56%; range, 34%-73%). Cornified cells predominated in the nasal smears from the postmenopausal women (median, 71%; range, 60%-77%) and the prepubertal girls (median, 77%; range, 67%-81%) at all times tested. CONCLUSION Cell turnover in the nasal epithelium may be related to hormonal state, and investigation of the mechanisms underlying such change should help in identifying possible functional consequences and in treating nasal symptoms associated with the female reproductive cycle.