Pemphigoid gestationis (PG) is a rare itching bullous disease of pregnancy and the postpartum period. We describe the use of a new methodology for measuring the nature and intensity of itching in a 21-year-old woman with pemphigoid gestationis. At 19 weeks gestation, she developed an itchy rash over the limbs, which spread to the trunk. Blisters then appeared on the hands which subsequently also involved the feet. Intense nocturnal wrist activities in this patient, measured with a wrist monitor and defined as average acceleration in the early hours of sleep, were even higher than that in patients with severe eczema, with an average value of 181.00 ± 43.49 (mean ± standard error) g/min for the first three hours, versus 84.47 ± 8.53 g/min for the group of 24 eczema subjects. Most wrist activities were slower movements at 0 to 1 Hz. This is in striking contrast to the scratching activities at 0 to 3 Hz in eczema subjects. There have been no therapeutic trials for PG. Topical steroid and oral antihistamines are usually ineffective, but worked in our patient. We also discuss the potential application of the monitor in assessing the nature of various dermatological or systemic itching disorders.