ORIGINAL CONTRIBUTION Skin Denervation and Cutaneous Vasculitis in Eosinophilia-Associated Neuropathy Chi-Chao Chao, MD; Sung-Tsang Hsieh, MD, PhD; Chia-Tung Shun, MD; Song-Chou Hsieh, MD, PhD Background: Eosinophilia is frequently associated with Main Outcome Measures: Quantitation of epider- peripheral neuropathy, and neuropathic pain is a major mal innervation, immunopathological findings of the cu- presentation. Little is known about the involvement of taneous vasculature, and motor disability grade. sensory nerve terminals and the vasculature in the skin of patients with eosinophilia. Results: Six patients fulfilled the criteria of Churg- Strauss syndrome, and the other 6 patients were catego- Objectives: To investigate the skin innervation and the rized as having primary eosinophilia. All of the 12 pa- pathological abnormalities of the cutaneous vasculature tients had mononeuropathy multiplex or polyneuropathy and their clinical significance in eosinophilia-associated with sensory symptoms as the initial manifestation. In- neuropathy. traepidermal nerve fiber densities were reduced in 10 pa- tients (83.3%), being significantly lower than in the con- Design: Case series. trols (mean±SD, 2.12±2.30 vs 10.56±3.69 fibers/mm, respectively; PϽ.001) and negatively correlated with the Setting: National Taiwan University Hospital, Taipei, Taiwan. disability grade (P=.003). Nine patients (75.0%), includ- ing all of the 6 patients with Churg-Strauss syndrome, Patients: Twelve patients with neuropathy and con- had cutaneous vasculitis, and two-thirds of the 9 pa- comitant eosinophilia (with an eosinophilic ratio of white tients had perivascular infiltration of eosinophils. blood cell classification Ͼ10% or absolute eosinophil count of Ͼ1000/µL). Conclusion: Skin denervation with cutaneous vasculi- tis is a major manifestation of eosinophilia-associated Interventions: Clinical assessments of neurological defi- neuropathy. cits, laboratory tests, nerve conduction studies, and a skin biopsy specimen 3 mm in diameter taken from the dis- tal leg without active skin lesions. Arch Neurol. 2007;64(7):959-965 OSINOPHILIA IS FREQUENTLY tion of T cells and macrophages, suggest- associated with inflamma- ing the nature of the immune-mediated tory and autoimmune dis- vasculopathy.6,7 orders, eg, necrotizing vas- culitis in Churg-Strauss 1 See also pages 935, Esyndrome (CSS). Scattered reports have 966, and 974 Author Affiliations: indicated the frequent association of Departments of Neurology eosinophilia with various types of neu- (Drs Chao and S.-T. Hsieh), ropathies based on nerve biopsies.2,3 Tra- Skin innervation is reduced in inflam- Pathology (Dr Shun), and ditionally, the demonstration of eosino- matory neuropathies such as Guillain- Internal Medicine philic vasculitis in tissues depends on Barre´ syndrome, chronic inflammatory (Dr S.-C. Hsieh), National nerve or muscle biopsies.4,5 We recently demyelinating polyneuropathy, and au- Taiwan University Hospital, and demonstrated the feasibility of using skin toantibody-related neuropathy.8-10 Skin Departments of Anatomy and denervation has been demonstrated in Cell Biology (Dr S.-T. Hsieh) biopsies to investigate cutaneous vasculi- and Forensic Medicine tis in addition to exploring skin innerva- systemic inflammatory diseases includ- 6 (Dr Shun), National Taiwan tion ; in vasculitic neuropathy and sys- ing vasculitis and systemic lupus ery- 7,11 University College of Medicine, temic lupus erythematosus, there was thematosus. In lupus, the degree of Taipei, Taiwan. significant dermal vasculitis with infiltra- skin denervation is related to the extent (REPRINTED) ARCH NEUROL / VOL 64 (NO. 7), JULY 2007 WWW.ARCHNEUROL.COM 959 ©2007 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 10/03/2021 of cutaneous vasculitis.7 These findings raise the possi- the patients following established methods.9 Studied nerves bility that skin innervation is altered in eosinophilia. included sural, peroneal, tibial, median, and ulnar (motor Eosinophilic syndrome is associated with neuropa- and sensory) nerves. Abnormal results in nerve conduction thies of diverse manifestations, ranging from focal to sys- studies were defined as having reduced amplitude of com- temic neuropathies. In patients with CSS, sensory symp- pound motor action potentials or sensory action potentials, prolonged distal latencies, or slowing of nerve conduction toms and neuropathic pain are major initial symptoms, velocity. accounting for 50% of presentations.4 Among different subtypes of neuropathies, the effects of eosinophilia on SKIN BIOPSY AND small fibers have received less attention, and to our knowl- IMMUNOHISTOCHEMISTRY OF THE SKIN edge, skin innervation has not been extensively evalu- ated in eosinophilia-associated neuropathy before. After informed consent was obtained, a skin biopsy specimen In this study, we investigated the following: (1) whether 3 mm in diameter was taken from the distal lateral leg 10 cm eosinophilia could be demonstrated in cutaneous tis- proximal to the lateral malleolar process. No active skin lesion sues; (2) whether there was associated dermal vasculi- was noted at the site of biopsy in any patient. If the sensory tis; and (3) whether skin innervation was altered in eo- symptoms were discrepant between the right and left legs, the sinophilia-associated neuropathy. side with the more severe symptoms was sampled. The sampled skin tissue was fixed in 4% paraformaldehyde overnight. Sec- tions 50 µm thick and perpendicular to the dermis were cut METHODS on a sliding microtome, quenched with 1% hydrogen perox- ide in methanol, and blocked with 5% normal goat serum. SUBJECTS Sections were incubated with rabbit antiserum to protein gene product 9.5 (1:1000; UltraClone, Isle of Wight, England) The criteria of eosinophilia-associated neuropathy included overnight. Protein gene product 9.5 is a ubiquitin carboxyl- the following: (1) clinical evidence of symptomatic periph- terminal hydrolase that labels myelinated and unmyelinated eral neuropathy; (2) eosinophilia according to an elevated nerve fibers in the peripheral nervous system. Sections were Ͼ ratio of white blood cell classification ( 10%) or the abso- then incubated with biotinylated goat antirabbit IgG (Vector Ͼ lute eosinophil count ( 1000/µL); and (3) the absence of Laboratories, Burlingame, California) for 1 hour and avidin- diabetes mellitus, renal impairment, malignancies, and spe- biotin complex (Vector Laboratories) for another hour. The cific autoimmune diseases including systemic lupus ery- reaction product was demonstrated using chromogen SG thematosus, rheumatoid arthritis, Sjo¨gren syndrome, and (Vector Laboratories). scleroderma. Patients fulfilling these criteria were recruited from National Taiwan University Hospital, Taipei, Taiwan, QUANTITATION OF from January 1, 1997, to December 31, 2005. In addition to detailed neurological examinations, patients EPIDERMAL INNERVATION also had laboratory tests carried out, including plasma glu- Epidermal innervation was quantified according to estab- cose level, functional tests of the liver and kidney, and levels 9 of antinuclear antibody, rheumatoid factor, anti-Sjo¨gren syn- lished criteria in a coded fashion. Observers were blinded to the clinical information. Protein gene product 9.5–positive nerves drome A antigen, anti-Sjo¨gren syndrome B antigen, anti- ϫ Smith antigen, antiscleroderma antigen (Scl-70), C3 and C4 in the epidermis of each skin section were counted at 40 mag- complement, and cryoglobulin. Possible malignancies were ex- nification with a BX40 microscope (Olympus, Tokyo, Japan). cluded by examining tumor markers (carcinoembryonic anti- Each individual nerve with branching points after crossing the gen and carbohydrate antigen 19-9), abdominal echo, and chest basement membrane was counted as a single nerve. Epider- radiography results. Parasite infections were screened by stool mal nerves splitting below the basement membrane were counted ovum examinations. If patients had a history of asthma, chest as 2 nerves. The length of the epidermis along the upper mar- radiography and computed tomography were performed to de- gin of the stratum corneum in each skin section was measured termine whether there was pulmonary infiltration. A diagno- using Image-Pro PLUS (Media Cybernetics, Silver Spring, Mary- sis of CSS followed the definition of the American College of land). Intraepidermal nerve fiber (IENF) density was hence de- Rheumatology subcommittee.12 In this article, if patients with rived and expressed as the number of fibers per millimeter of eosinophilia-associated neuropathy did not have CSS, malig- epidermal length. In the distal leg, the mean±SD (fifth percen- nancies, or parasitic infections, this subtype of eosinophilia was tile) normative values of IENF densities from our laboratory classified as primary eosinophilia. were 11.16±3.70 (5.88) fibers/mm for subjects younger than 60 years and 7.64±3.08 (2.50) fibers/mm for subjects aged 60 The ability of ambulation was assessed by a disability grade 7 from 0 to 6: grade 0 indicated normal neurological status; grade years or older. 1, minor signs or symptoms capable of running; grades 2 and 3, ambulation without and with assistance, respectively; grade PATHOLOGICAL ASSESSMENT OF VASCULITIS 4, wheelchair bound or bed bound; grade 5, requiring mechani- IN SKIN BIOPSY SPECIMENS cal ventilation; and grade 6, death.13 This study was reviewed and approved by the ethics com- Biopsy specimens