Objective Odor Assessment in Patients with Osmidrosis

No standards for the assessment of axillary odor intensity and the effects of therapy for osmidrosis have been established. This study presents an objective method for assessing odor severity in patients with osmidrosis and investigates the volatile odorants and skin flora.

The odor intensity was measured pre- and postoperatively using an industrial odor sensor in 79 patients with osmidrosis. Cultures of the axillary skin were obtained during skin flap surgery. Volatile odorants of the patients were assessed using an odor-sensor gas chromatograph mass spectrometer, and samples collected from clothing worn by the patients before and after surgery. The skin pH of the axilla was measured before and after surgery. The locations of odorants and bacteria in the skin were observed using electron microscopy.

The mean patient age was 28.8 years, and the male-to-female ratio was 4:3. The odor significantly decreased from 52.6 preoperatively to 20.5 postoperatively (P < 0.001). The bacterial flora on the skin included mostly Staphylococcus. Multiple causative substances (volatile proteins) were identified on gas chromatography. The mean preoperative axillary skin pH was 6.21, which was significantly different than that of patients without osmidrosis (5.92; P < 0.01).

An odor sensor accurately assesses odor intensity in patients with osmidrosis. The neutralization of axillary pH may promote the production of odorants by creating the optimal pH for bacterial growth. Odor sensor and pH values can be used pre- and postoperatively as objective assessment measurements for patients with osmidrosis.