Measurement of pruritus in a Chinese woman with pemphigoid gestationis using a wrist movement detector

Authors

  • Kam-lun Ellis Hon FAAP,

    1. From the Dermatology Research Centre, and Department of Paediatrics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong
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  • Lai-shan Mona Chiu MRCP,

    1. From the Dermatology Research Centre, and Department of Paediatrics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong
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  • Man-chin Adrian Lam BSc, MPhil,

    1. From the Dermatology Research Centre, and Department of Paediatrics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong
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  • Cheung-lung Paul Choi FRCPA,

    1. From the Dermatology Research Centre, and Department of Paediatrics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong
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  • Shirley Chan MRCP,

    1. From the Dermatology Research Centre, and Department of Paediatrics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong
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  • Nai-ming Luk MRCP

    1. From the Dermatology Research Centre, and Department of Paediatrics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong
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Kam-lun Ellis Hon, faap Department of Paediatrics The Chinese University of Hong Kong6/F, Clinical Sciences BuildingPrince of Wales Hospital Shatin Hong Kong
E-mail: ehon@cuhk.edu.hk

Abstract

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.

Introduction

We describe the use of a wrist motion monitor in a woman with pemphigoid gestationis (PG) and discuss the potential application of the monitor in assessing the nature of various dermatological or systemic itching disorders.

Case Report

A 21-year-old woman presented with an itchy generalized bullous eruption. 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. There was no fever, oral or genital lesions and she denied the use of over-the-counter or herbal medicine.

Upon examination, she had multiple erythematous patches and plaques over the trunk and limbs. Bullae were seen on the limbs, particularly on the hands and feet. Mucosal membranes were spared. A skin biopsy was performed, which showed palmoplantar skin with eosinophilic spongiosis, psoriasiform hyperplasia, and intra-epidermal vesicles. Basal vacuolar alteration was evident. There were superficial and mid-interstitial inflammatory and eosinophilic infiltrates. Immunofluorescence study showed a strong linear dermo-epidermal junction stain of C3. The collection of eosinophils at papillary dermis attempting to form sub-epidermal blisters and the strong immunofluorescein stain for C3 confirmed the diagnosis of PG.

Her nocturnal itch pattern was documented with the DigiTrac wrist monitor (Fig. 1, IM Systems, Baltimore, MD, USA)1 showing intensive scratching movements, which was more than double the intensity of scratching in patients with severe atopic dermatitis (AD), with an average value of 181.00 ± 43.49 (mean ± SE) g/min for the first 3 h (Figs 2 & 3). Most wrist activities are slow movements at 0–1 Hz. The wrist activities of a normal person and that of a patient with severe eczema were also shown as reference.

Figure 1.

The DigiTrac motion monitor was worn on the dominant hand before bed resting. It would continuously record wrist movements until the next morning

Figure 2.

Average g activities of (a) the woman with pemphigoid gestationis (PG), (b) a 21-year-old man with severe atopic dermatitis (AD), and (c) a normal 21-year-old woman as reference. The vertical axis indicates the total amount of wrist activities as a g value and the horizontal axis indicates the time and date when the movements occur

Figure 3.

Frequency spectrum in the early hours of sleep of (a) the woman with pemphigoid gestationis (PG), (b) a 21-year-old man with severe atopic dermatitis (AD), and (c) a normal 21-year-old woman as reference. In the three-dimensional diagrams, the vertical axis represents the wrist activities as a g value, the horizontal axis indicates the frequency in Hz that the dominant hand scratches, and the remaining axis indicates the time and date when the movements occur. Note that most activities occur at 0–2 Hz

The patient was symptomatically treated with chlorpheniramine maleate and topical corticosteroid (flucinolone acetonide 0.025%) and her skin symptoms resolved over a period of 2 weeks. She was also treated as having Graves’ disease with propyl thiouracil (50 mg, twice daily) for 2 months.

Discussion

Pemphigoid gestation is a rare itching bullous disease of pregnancy and the postpartum period, with an estimated incidence of 1 in every 50,000 pregnancies.2–7

There have been no therapeutic trials for PG. Topical steroid and oral antihistamines are usually ineffective, but worked in our patient.2 Mainstay of treatment is systemic steroid.2 Most will respond to 0.5 mg.kg of prednisolone daily. Maintenance dose is usually not required.

The itch pattern, as documented by the DigiTrac wrist-held movement monitor,1 showed intense nocturnal itch (Figs 2 & 3). Itching and scratching are important symptoms in various dermatological and systemic disorders. Their quantification is clinically important but has been difficult.1 The DigiTrac monitor is a wrist-worn device for recording the frequency and amplitude of limb movements. It is normally used by athletes to record exercise activities. There has been no report to date as to its scientific usage other than in AD. It provides fast Fourier transformation three-dimensional contourgraphy (indicating frequency of the detected movements over the selected period of time), average spectral plots (average spectral content for the entire time shown in the contourgraph), spectral power and a programmable start-up time. Therefore, the monitor shows both qualitative and quantitative information.1 The application of the DigiTrac is simple. The patient is instructed to wear the DigiTrac monitor (IM Systems) on his or her dominant wrist before sleeping. In our pilot testing on 17 AD patients,8 the DigiTrac was found to be able to provide essential data on a wide spectrum of frequencies of wrist movements and quantity of movements in term of acceleration or g values. The monitor was programmed to record limb motion between 10 p.m. and 8 a.m. the following day. The contour was assessed to determine if different patterns could be distinguished between AD patients and controls. The data were then downloaded to a computer using DigiTrac 3.9 (IM Systems). Wrist activities were expressed in unit of average value of acceleration (g/min).

We previously documented that wrist activities between 0 and 3 Hz for the first 3 h are a good indicator of eczema severity, nocturnal itch, and sleep disturbance in children.1 We found that intense nocturnal wrist activities in this patient, 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 ± SE) g/min for the first 3 h vs. 84.47 ± 8.53 g/min for the group of 24 eczema subjects.1 Most wrist activities were slower movements at 0–1 Hz. This is in striking contrast to the scratching activities at 0–3 Hz in eczema subjects. The itch was relieved by antihistamine and topical corticosteroid. The intense scratching and discomfort experienced by patients with PG must not be underestimated.

We also applied the monitor in a previously healthy 3-year-old girl with a 4-week history of generalized itch without a rash (personal data). She had no past history of atopy or skin dryness. Despite the severe itch, she had only minimal scratch marks on her right gluteal region but no flexural involvement. The girl was treated for scabies and eczema with oral antihistamines by various dermatologists without improvement. She subsequently presented with right hip pain and fever to a regional hospital. Radiological and histopathological investigations confirmed that she had a rare peripheral T-cell lymphoma. The itch pattern prior to and following chemotherapy, as documented by the DigiTrac wrist-held movement monitor, showed a dramatic reduction of her nocturnal itch. The pattern was also very different from that for eczema in that the scratching was of much higher intensity but lower frequency. The report serves to alert clinicians of the gold paradigm that in a patient with new-onset generalized itch without a rash, lymphoma and other malignancies must be considered.

In conclusion, this case of PG illustrates that the scratching and discomfort experienced by patients with PG was intense and must not be underestimated. We believe that itching and scratching are complicated neuropsychologic processes, and patients with various diseases may itch differently in terms of scratching frequencies or average accelerations. As itch is difficult to document objectively, the DigiTrac monitor can help determine on its management, such as the choice of various sedating antihistamines or initiation of systemic corticosteroid if the itch is severe. DigiTrac may also be helpful in monitoring its intensity and frequency before and following treatments.