Albuquerque, C

Cunha, F

Lito, D

Santos, J

Almeida Santos, J

Repositório Comum

American Journal of Emergency Medicine xxx (2014) xxx–xxxContents lists available at ScienceDirectAmerican Journal of Emergency Medicinej ourna l homepage: www.e lsev ie r .com/ locate /a jemCorrespondenceBenign acute childhood myositis: an alarming condition with anexcellent prognosis!☆To the Editor,Benign acute childhood myositis (BACM) causes difficulty to walkdue to severe bilateral calf pain. We report the clinical and laboratoryfeatures of children admitted with BACM to a level II hospital'spediatric department, from January 2001 to December 2012(12 years). Data were collected retrospectively from patient's clinicalrecords. The purpose was to characterize BACM's clinical picture,providing greater awareness to its benign course and helping todifferentiate it from more serious disorders.Twenty-eight admissions were identified (2.5/1000 admissions),corresponding to 25 children (Table). There was a 4.6:1 male:femaleratio (21 boys, 84%). Median age was 7 years (range, 4-10 years), and82% were older than 5 years. Most cases were seen from 2008 to 2010(n = 19, 67.9%) and during winter and spring (n = 20, 71.4%) (Figs. 1and 2). All occurred at the early convalescent phase of an upperrespiratory infection. History of recent trauma or vigorous exercise andfamily history of neuromuscular disorders were negative. On physicalexamination at the pediatric emergency department, all patients wereunable to walk/bear weight. Bilateral gastrocnemius-soleus muscleswere tender tomild palpationwithout other inflammatory signs. Lowerextremity sensation was intact, with normal strength, tone, and deeptendon reflexes. Children were admitted for clinical and laboratoryfollow-up because of serious functional impairment (n= 24, 85.7%) orprevious history of BACM/recurrence (n= 4). The following laboratoryabnormalitieswere detected (Table): leukopenia (n=10), neutropenia(n = 7), thrombocytopenia (n = 6), and mildly elevated C-reactiveprotein (CRP) (n = 2). All children presented a markedly elevatedserum creatine kinase (CK); median admission value was 4181 UI/L(range, 785-26863 UI/L). In the 22 available aminotransferase results,aspartate transaminase (AST) was elevated in all, with a less increasedalanine transaminase (ALT) level in 12 cases. Blood urea nitrogen,creatinine, electrolytes, andurinalysiswere normal. Serologic testswereperformed in 20 cases (71.4%), with 9 positive results (Table):Mycoplasma pneumoniae (n = 3), cytomegalovirus and influenza A(n = 2), and influenza B and adenovirus (n = 1).Median admission period was 3 days (range, 1-7 days), and allchildren revealed clinical and laboratory improvement with sup-portive therapy (bed rest, intravenous hydration, and oral ibupro-fen). No red to brown urine or renal/hydroelectrolytic abnormalitieswere seen. Children with recurrent episodes were reassessed atpediatric consultation 1month after discharge, with full recovery andnormal CK levels. The remaining patients were referred to theirattending physician.☆ Conflict of interest: None.0735-6757/© 2014 Elsevier Inc. All rights reserved.Please cite this article as: Santos JA, et al, Benign acute childhood myosiMed (2014), http://dx.doi.org/10.1016/j.ajem.2014.08.022Benign acute childhoodmyositis is a rare disorder and continuesto lead physicians into unnecessary workup when they areunfamiliar with its presentation [1-5]. Most commonly occurafter influenza B and occasionally influenza A infection, butparainfluenza, adenovirus, herpes simplex, Epstein-Barr,Coxsackie, rotavirus, and M pneumoniae have also been implicated[1-3,5-10], as found in our study. As evidenced, key elements in thediagnosis are a preceding upper respiratory infection followed bythe acute onset of typical myositis clinical findings, predominantlyaffecting gastrocnemius-soleus muscles. Further clinical featuresinclude school-aged boys and late winter–early spring predomi-nance, elevated CK, and aminotransferase levels (especially AST)[1-10]. Transient hematological abnormalities (mild leukopenia,neutropenia, and thrombocytopenia) are also seen [1,3,8-10].Erythrocyte sedimentation rate and CRP are usually normal butmay be mildly elevated [1-3,5,6]. Patients with this typical clinicalpresentation can be treated as an outpatient [1,5]. However, as seenin our study, some children are admitted for hydration, observa-tion, and serial CK levels to rule out any progression to rhabdomy-olysis [1,6,8-10]. Recurrence is rare and has been demonstrated tobe caused by different viruses or different influenza types [9]. In ourstudy, 3 children had recurrent episodes with more than a yearinterval, and they totally recovered in between. If different etiologicagents were behind these episodes, it was not possible to assess.Treatment is supportive, and antivirals are unlikely to be beneficial[2-5]. The hallmark of BACM is its spontaneous and rapid clinicalresolution within 1 week [1-5]. In this study, all children fullyrecovered within a week or less only with supportive measures.Higher CK levels were not associated with acute renal failure,progression to rhabdomyolysis, or other complications. Patientscan be discharged if they have typical presentation, normal renalfunction, and follow-up to ensure complete resolution [2,10].Further investigation is not indicated unless there is clinicalconcern for more serious disorders [1,6,8,10]. Findings notclassically associated with BACM include myoglobinuria, recenttrauma or vigorous exercise, family history of neuromusculardisorders, subacute or chronic progression, a new rash, frankmuscle weakness, or abnormal neurologic findings. When suchatypical features are present, other diagnosis as rhabdomyolysis,Guillain-Barré syndrome, primary inflammatory myositis, muscu-lar dystrophy, or metabolic disease must be excluded [2,6,8,10].Benign acute childhood myositis should be part of the broaddifferential diagnosis of a child unable to walk/bear weight.Although potentially alarming, it is self-limited with an excellentprognosis. Recognition of this rare clinical entity by the emergencyphysician is essential to prevent unnecessary invasive testing andhospital admission.tis: an alarming condition with an excellent prognosis!, Am J EmergTableClinical and laboratory features of 25 children admitted with BACMChild no. Sex Age (y) Admission main criteria WBC(×109/L)ANC(×109/L)Platelet count(×109/L)CRP(mg/L)Admission CK (UI/L) AST(UI/L)ALT(UI/L)Serology(IgM+)Hospitalstay (d)1 M 7 FI 8.5 N N N 4095 NA NA – 22 M 10 FI 3.0 1.341 N N 4369 NA NA – 43 M 4 FI 8.1 N N N 4275 NA NA Influenza B 24 M 10 FI 2.6 0.754 N N 6629 428 90 – 25 M 7 FI 4.8 N N N 5020 234 56 CMV 36 M 6 FI 5.2 N N N 10157 352 69 – 27 M 5 FI 4.6 N N N 7125 124 31 – 38 M 10 FI 4.6 N N N 2329 103 30 – 29 M 10 FI 4.4 N 145 N 6022 288 95 – 210 M 7 FI 4.2 1.218 N N 1582 133 29 M. pneum 211 F 5 FI 2.4 0.823 145 N 4267 157 52 M. pneum 312 M 8 FI 3.8 N N N 1250 59 18 – 213 M 5 R 2ndepisode 5.3 N N 25 6790 NA NA Influenza A 414 M 5 FI 6.3 N N N 6466 NA NA CMV 315 M 6 FI 5.7 N N 52 3927 141 40 Adenovírus 516 M 7 FI 2.6 0.762 63 N 3156 NA NA M. pneum 713 M 6 R third episode 5.6 N N N 785 157 71 – 417 M 10 FI 3.1 1.240 N N 2815 134 41 – 318 M 10 5.5 N N N 2049 149 68 – 419 F 8 FI first episode 4.2 N 123 N 26863 907 21 – 220 M 8 FI 3.3 1.340 N N 1455 79 32 – 221 F 6 FI 4.5 N 93 N 3298 117 35 – 319 F 9 R second episode 3.9 N 109 N 10979 387 94 Influenza A 522 M 7 FI 5.3 N N N 1064 158 17 – 223 M 8 FI first episode 5.2 N N N 21492 1070 203 – 624 F 8 FI 3.3 N N N 3271 91 29 – 125 M 5 FI 3.3 N N N 1851 106 37 – 223 M 9 R second episode 5.8 N N N 14453 451 108 – 7Median abnormal values 3.2 1.218 116 38.5 4181 153 70Child 13, 19, and 23 presented recurrent episodes (child 13 had a previous episode out of the study period). Bold numbers indicate abnormal values. Reference range: CRP, less than 5mg/L; CK, 31 to 152 UI/L; AST, less than 31 UI/L; ALT, less than 39 UI/L. Leukopenia: white blood cell count less than 4 × 109/L; neutropenia: absolute neutrophil count less than 1.5 ×109/L; thrombocytopenia: platelet count less than 150 × 109/L. Viral and bacterial identificationwas based on serologic tests with a positive immunoglobulinM result. Abbreviations:ANC, absolute neutrophil count; CMV, cytomegalovirus; F, female; FI, functional impairment; IgM, immunoglobulin M; M, male; M. pneum, Mycoplasma pneumoniae; n, absolutenumber; N, normal value; NA, not available; R, recurrence; WBC, white blood cell count.01234567892001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012Number of admitted casesYearFig. 1. Annual distribution of admitted cases with BACM. Most cases were seen from2008 to 2010 (n = 19, 67.9%).012345678910Jan Feb March April May June July Aug Sept Oct Nov DecNumber of admitted casesMonthFig. 2.Monthly distribution of admitted cases with BACM. Most cases were seen duringwinter and spring.2 Correspondence / American Journal of Emergency Medicine xxx (2014) xxx–xxxPlease cite this article as: Santos JA, et al, Benign acute childhood myosiMed (2014), http://dx.doi.org/10.1016/j.ajem.2014.08.022Joana Almeida Santos MDPediatric Department, Hospital Dona EstefâniaCentro Hospitalar Lisboa Central Lisbon, PortugalE:mail address: joanaasantos@gmail.comCarolina Albuquerque MDDavid Lito MDFlorbela Cunha MDPediatric DepartmentHospital de Vila Franca de XiraVila Franca de Xira, PortugalE:mail addresses: carolinalbuquerque@gmail.com (C. Albuquerque),dmlito@gmail.com (D. Lito), flor.cunha@gmail.com (F. Cunha)http://dx.doi.org/10.1016/j.ajem.2014.08.022References[1] Hall G, Schranz CI. Benign acute childhood myositis—a rare cause of abnormal gait.Am J Emerg Med 2014;32(2):193.e1–2.[2] Heiner JD, Ball VL. A child with benign acute childhood myositis after influenza.J Emerg Med 2010;39(3):316–9.[3] Koliou M, Hadjiloizou S, Ourani S, Demosthenous A, Hadjidemetriou A. A case ofbenign acute childhood myositis associated with influenza A (H1N1) virusinfection. Clin Microbiol Infect 2010;16(2):193–5.[4] Neocleous C, Spanou C, Mpampalis E, Xatzigeorgiou S, Pavlidou C, Poulos E, et al.Unnecessary diagnostic investigations in benign acute childhood myositis: a caseseries report. Scott Med J 2012;57(3):182.[5] RubínE,De laRubia L, PascualA,Domínguez J, Flores C. Benignacutemyositis associatedwith H1N1 influenza A virus infection. Eur J Pediatr 2010;169(9):1159–61.[6] Agyeman P, Duppenthaler A, Heininger U, Aebi C. Influenza-associated myositis inchildren. Infection 2004;32(4):199–203.tis: an alarming condition with an excellent prognosis!, Am J Emerg3Correspondence / American Journal of Emergency Medicine xxx (2014) xxx–xxx[7] Hu JJ, Kao CL, Lee PI, Chen CM, Lee CY, Lu CY, et al. Clinical features of influenzaA and B in children and association with myositis. J Microbiol Immunol Infect2004;37(2):95–8.[8] Jain S, Kolber MR. A stiff-legged gait: benign acute childhood myositis. CMAJ 2009;181(10):711–3.Please cite this article as: Santos JA, et al, Benign acute childhood myosiMed (2014), http://dx.doi.org/10.1016/j.ajem.2014.08.022[9] King BA. Benign acute childhood myositis as a cause of failure to weight bear. JPaediatr Child Health 2003;39(5):378–80.[10] Rennie LM, Hallam NF, Beattie TF. Benign acute childhood myositisin an accident and emergency setting. Emerg Med J 2005;22(10):686–8.tis: an alarming condition with an excellent prognosis!, Am J Emerg

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Benign acute childhood myositis: an alarming condition with an excellent prognosis!

Joana Almeida Santos

Carolina Albuquerque

David Lito

Florbela Cunha

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The American Journal of Emergency Medicine

Repository of the Hospital Center of Central Lisbon

Benign Acute Childhood Myositis: an Alarming Condition With an Excellent Prognosis!

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Benign Acute Childhood Myositis: an Alarming Condition With an Excellent Prognosis!

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