Acta Dermato-Venereologica issue 50:1 98-1CompleteContent | Page 21

82 CLINICAL REPORT Brachioradial Pruritus and Notalgia Paraesthetica: A Comparative Observational Study of Clinical Presentation and Morphological Pathologies Manuel P. PEREIRA, Hannah LÜLING, Annette DIECKHÖFER, Sabine STEINKE, Claudia ZEIDLER and Sonja STÄNDER Department of Dermatology and Center for Chronic Pruritus, University Hospital Münster, Münster, Germany Brachioradial pruritus (BRP) and notalgia paraesthe- tica (NP) represent 2 of the most common neuropathic itch syndromes. A total of 58 consecutive patients pre- senting at the Center for Chronic Pruritus, University Hospital Münster, were analysed with regard to clini- cal presentation, anatomical and morphological pat- hologies, impairment in quality of life, and response to treatment with topical capsaicin. Patients with BRP reported stinging and burning more often than those with NP. In the BRP group structural magnetic reso- nance imaging abnormalities more frequently correla- ted with localization of the symptoms compared with in patients with NP. In addition, intraepidermal nerve fibre density was decreased in lesional skin in patients with BRP, but not in those with NP, confirming the neuropathic origin in BRP. Topical capsaicin resulted in a significantly higher alleviation of itch and pain in- tensity and improvement in quality of life in patients with BRP compared with those with NP, which may re- flect clinical and aetiological differences between the conditions. Key words: dermatome; intraepidermal nerve fibre density; pain; pruritus; quality of life; radiculopathy. Accepted Sep 13, 2017; Epub ahead of print Sep 13, 2017 Acta Derm Venereol 2018; 98: 82–88. Corr: Sonja Ständer, Department of Dermatology and Center for Chro- nic Pruritus, University Hospital Münster, Von-Esmarch-Str. 58, DE-48149 Münster, Germany. E-mail: [email protected] N europathic itch syndromes are responsible for ap- proximately 8% of cases of chronic pruritus (1, 2), a highly prevalent and burdensome interdisciplinary symptom as revealed by the Global Burden of Disease (GBD) project (3). Disturbances at any level of the somatosensory system, from the peripheral fibres to the central nervous system, may lead to neuropathic itch syndromes (4). These syndromes share common proper- ties, such as accompanying paraesthetic and dysaesthetic symptoms and relief through the application of cold to the skin (ice-pack sign). Symptoms may vary in their localization and intensity according to the level at which the somatosensory disturbance occurs and the underlying neuropathic mechanism (5, 6). Several different condi- tions may cause neuropathic itch syndromes, including systemic diseases (e.g. diabetes mellitus), radiculopathy due to nerve impingement, dermatological conditions doi: 10.2340/00015555-2789 Acta Derm Venereol 2018; 98: 82–88 (e.g. chronic prurigo, sensitive skin) or iatrogeny (e.g. chemotherapy); often the cause is unknown (idiopathic) (7). Compression syndromes at the spinal level constitute relevant conditions frequently overlooked in the clinical routine (7, 8). These may develop as a result of dege- nerative alterations of the vertebral column, anatomical variations, tumours, abscesses or aneurysms (7). In brachioradial pruritus (BRP), compression of the cer- vical spinal cord or the spinal ganglia at C5/C6 occurs, causing unilateral or bilateral pruritus in the forearms (9, 10). Compression of the dorsal branches of the spinal nerves (T2–T6) leads to circumscribed pruritus between the scapulae, a condition known as notalgia paraesthetica (NP) (2, 11). These compression syndromes are often accompanied by other paraesthetic symptoms, such as stinging, tingling or burning sensations, and may lead to lichenification, excoriations or post-inflammatory hyper- pigmentation as a result of chronic scratching (2, 7). If the symptoms remain localized, topical capsaicin, a transient receptor potential cation channel vanilloid-1 (TRPV-1) agonist, is the first-line topical therapy (12–14). Although compres sion of large nerve fibres occurs in both BRP and NP, quotidian clinical practice suggests differences with regard to their clinical presentation and, especially, with regard to the response to topical capsaicin (15). The aim of this retrospective study of routine clini- cal data was to characterize both syndromes and compare them with regard to clinical presentation (itch intensity, accompanying paraesthetic symptoms), morphological pathologies (cervical/thoracic magnetic resonance ima- ging (MRI), intraepidermal nerve fibre density (IENFD)) in lesional skin, psychological co-morbidities (anxiety and depression), impairment in quality of life (QoL) and response to topical capsaicin. METHODS Subjects Successive adult patients with BRP and NP presenting at the Department of Dermatology, Center for Chronic Pruritus at the University Hospital Münster, Germany, were considered for inclusion in this retrospective analysis of routine clinical data. Pa- tients were treated and diagnosed according to German guidelines (16). The diagnosis of BRP or NP was performed according to the medical history (localization of symptoms at the onset of the disease, quality of the paraesthetic symptoms, positive ice-pack This is an open access article under the CC BY-NC license. www.medicaljournals.se/acta Journal Compilation © 2018 Acta Dermato-Venereologica.