Generalized chronic pruritus with fibromyalgia

Abstract

A 47-year-old female patient presented to our outpatient clinic with pruritus that had been present for nine years. Initially, the symptoms had started on the trunk and the upper arms on unaffected skin. Over the years, a generalization of the pruritic sensations had occurred. Both the intensity and the quality of the sensations were described as highly variable. In addition to the pruritus, the patient also reported burning and aching sensations. During provision of her medical history, the patient also reported that sweating worsened the symptomatology, while external rehydration would provide short-term relief. The intensity was reported on the visual analog scale (VAS 0–10) with an average score of 5.3 and a maximum score of 6.3 in the last four weeks. The current ItchyQoL to assess quality of life for pruritus was 48.4 points (0–30: mild impairment; 31–50: mild impairment; 51–80: moderate impairment; 81–110: severe impairment). At the time of onset of pruritus, the patient was diagnosed with fibromyalgia. There were no other previous diseases. The patient had an atopic diathesis with an EAS (Erlangen Atopy Score) of 13.5 points with multiple type IV sensitizations to nickel (II) sulfate, rosin, turpentine, Peru balsam and tolu balsam, among others. Remaining dermatological and family history was unremarkable. Ongoing medication at the time of presentation was duloxetine and tapentadol for the treatment of fibromyalgia. The use of the μ-opioid agonist tapentadol was unrelated to the pruritus, which had started several weeks before the drug was taken and persisted even when tapentadol therapy was interrupted. The skin findings survey revealed no abnormalities, no xerosis cutis, and a red dermographism. In the laboratory chemistry tests, the differential blood count, electrolytes, liver and kidney values, HbA1c, ferritin, vitamin B12, and folic acid displayed no pathological findings. Quantification of intraepidermal nerve fiber density (sampling site: 10 cm proximal to the right lateral malleolus) revealed a markedly reduced finding of 0.78 fibers/mm (Figure 1a). Figure 1b shows a normal finding for women aged 40–59 (>10.55 fibers/mm). Based on the medical history and clinical findings, we made the diagnosis of small fiber neuropathy in fibromyalgia. An atopic diathesis was present as a cofactor. The diagnosis was confirmed by determination of nerve fiber density. After a frustrating pretreatment period with high doses of antihistamines, oral glucocorticosteroids and gabapentin, a change to pregabalin therapy was recommended. However, this did not lead to an alleviation of the symptoms. In addition, consistent lipid replenishment of the skin with topical preparations containing urea and menthol was recommended, which may contribute to pruritus reduction in xerosis cutis [1]. The present case report shows fibromyalgia as the cause of chronic generalized pruritus in the presence of small fiber neuropathy. Fibromyalgia is a widely disputed clinical entity. It was defined in the 1990s using ACR (American College of DOI: 10.1111/ddg.14498 Generalized chronic pruritus with fibromyalgia Clinical Letter