Acta Dermato-Venereologica 99-7CompleteContent

681 SHORT COMMUNICATION Unilateral Remission of Psoriasis Associated with a Spinal Arteriovenous Malformation Daisuke WATABE 1 , Mitsutoshi TOMINAGA 2 , Hironori MATSUDA 2 , Kenji TAKAMORI 2 and Hiroo AMANO 1 Department of Dermatology, Iwate Medical University School of Medicine, 19-1 Uchimaru, Morioka, Iwate 020-8505, and 2 Institute for Environment and Gender-Specific Medicine, Juntendo University Graduate School of Medicine, Urayasu, Chiba, Japan. E-mail: dwatabe@ iwate-med.ac.jp 1 Accepted Mar 21, 2019; E-published Mar 21, 2019 Psoriasis is an immune-mediated chronic inflammatory skin disorder in which the IL-23/Th17 pathway is consi- dered to play a major pathogenetic role (1). However, re- cent studies have found evidence for interaction between the immune and nervous systems in the pathogenesis of psoriasis. We report here a case of psoriasis in which uni- lateral remission of the lesions was observed following myelopathy due to spinal arteriovenous malformation resulting in hypoesthesia of the right leg. CASE REPORT The patient was a 51-year-old Japanese man with a 10-year his- tory of plaque psoriasis involving the trunk and bilateral lower extremities. He had been treated with topical betamethasone dipropionate and calcipotriol. Four years before presentation, he had gradually developed muscle weakness and atrophy of the right lower limbs, as well as hypoesthesia behind the right knee. Neurological examination revealed weakness of the right iliopsoas muscle, quadriceps femoris muscle, hamstrings, anterior tibial muscle and gastrocnemius muscle. Hypoesthesia and hypopalles- thesia were noted in the right lower limb. The right Achilles reflex was absent. Spinal magnetic resonance imaging (MRI) revealed evidence of a spinal arteriovenous malformation (AVM) in the upper thoracic and lumbar region, and a diagnosis of myelopathy due to spinal AVM was made. At that time, physical examination revealed erythematous, indurated, slightly scaling plaques on the trunk and lower limbs. Interestingly, remission of the psoriatic plaques on the right knee and leg was observed (Fig. 1). The area of skin lesions on the right side largely resembled that on the left side before paresis. Three biopsy specimens were taken from the psoriatic plaque on the left leg, non-lesional skin on the left leg and a skin area showing remission of the psoriatic plaque in the area of neuropathy in the right leg. Histological examination of the biopsy specimen of psoriatic plaque revealed hyperkeratosis and elongation of the rete ridges with epidermal hyperplasia. An im- munofluorescence study showed that nerve fibres immunoreactive Fig. 1. Remission of psoriasis on the right knee and leg following myelopathy due to a spinal arteriovenous malformation resulting in hypoesthesia of the right leg. for the general neuronal marker, protein gene product 9.5 (PGP 9.5), were present mainly in the papillary dermis and increased in the psoriatic plaque relative to the non-lesional skin (Fig. 2a, Figs S1a and S2a 1 ) (for details of Materials and Methods, see Appendix S1 1 ). Intraepidermal nerve fibres were seen in the skin area showing remission on the paretic leg (Fig. 2a, Figs S1c and S2c 1 ). PGP9.5-immunoreactive nerve fibres were almost absent in the non-lesional skin (Fig. 2a, Figs S1b and S2b 1 ). Nerve fibres immunoreactive for PGP9.5/Substance P (SP) and PGP9.5/cal- citonin gene-related peptide (CGRP) were mainly present in the dermis and increased in the psoriatic plaque relative to the skin area showing remission on the paretic leg and almost absent in the non-lesional skin (Fig. 2b, c, Figs S1 and S2 1 ). https://www.medicaljournals.se/acta/content/abstract/10.2340/00015555-3177 1 Fig. 2. Semiquantitative analyses of the number of PGP9.5 (a), PGP9.5/SP (b) and PGP9.5/CGRP (c) immunoreactive nerve fibres in the psoriatic plaque, non-lesional skin and paretic skin. Values represent the means ± standard deviation (SD) of 9 specimens of each skin and were compared by 1-way analysis of variance (ANOVA) with Bonferroni’s comparison. *p < 0.05, **p < 0.01, ***p < 0.001. This is an open access article under the CC BY-NC license. www.medicaljournals.se/acta Journal Compilation © 2019 Acta Dermato-Venereologica. doi: 10.2340/00015555-3177 Acta Derm Venereol 2019; 99: 681–682

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