Journal List > Pediatr Allergy Respir Dis > v.21(2) > 1033157

Ah, Young, Hoon, Soon, Hyun, Bae, Min, and Hee: Clinical Study of Influenza B-Associated Myositis

Abstract

Purpose

Influenza B-associated myositis is an infrequent and poorly known complication of influenza B virus infection in children. The aim of this study was to describe the clinical and laboratory manifestations, diagnosis, and outcomes of influenza B-associated myositis in Korean children.

Methods

A retrospective analysis was conducted in patients aged <16 years who had been diagnosed with influenza B-associated myositis at the Catholic University Bucheon Saint Marys' Hospital between April 2010 and May 2010.

Results

Overall, 16 cases were analyzed. Influenza B-associated myositis typically occurred in preschool-aged children with a 3:1 male predominance. The mean age was 4.6 years (range, 3 to 7 years). The median interval between onset of influenza infection and onset of influenza B-associated myositis was 3 days (range, 1 to 7 days). Only the calf muscles were involved in all patients. Blood creatine phosphokinase concentration was elevated in most patients. Median duration to clinical recovery was 3 days (range, 1 to 4 days). No patient had rhabdomyolysis, renal failure, or related sequelae. All patients had a favorable outcome without administration of antiviral drugs.

Conclusion

Clinical and laboratory findings of influenza B-associated myositis are very characteristic and allow a rapid diagnosis during the influenza season. Outcomes of influenza B-associated myositis are good with only proper supportive treatment.

References

1. Carrat F, Vergu E, Ferguson NM, Lemaitre M, Cauchemez S, Leach S, et al. Time lines of infection and disease in human influenza: a review of volunteer challenge studies. Am J Epidemiol. 2008; 167:775–85.
crossref
2. Doyle WJ, Skoner DP, Hayden F, Buchman CA, Seroky JT, Fireman P. Nasal and otologic effects of experimental influenza A virus infection. Ann Otol Rhinol Laryngol. 1994; 103:59–69.
crossref
3. Hobbins TE, Hughes TP, Rennels MB, Murphy BR, Levine MM. Bronchial reactivity in experi-mental infections with influenza virus. J Infect Dis. 1982; 146:468–71.
crossref
4. Abe M, Higuchi T, Okada K, Kaizu K, Matsumoto K. Clinical study of influenza-associated rhabdomyolysis with acute renal failure. Clin Nephrol. 2006; 66:166–70.
crossref
5. Dietzman DE, Schaller JG, Ray CG, Reed ME. Acute myositis associated with influenza B infection. Pediatrics. 1976; 57:255–8.
6. Hu JJ, Kao CL, Lee PI, Chen CM, Lee CY, Lu CY, et al. Clinical features of influenza A and B in children and association with myositis. J Microbiol Immunol Infect. 2004; 37:95–8.
7. Mackay MT, Kornberg AJ, Shield LK, Dennett X. Benign acute childhood myositis: laboratory and clinical features. Neurology. 1999; 53:2127–31.
crossref
8. Zafeiriou DI, Katzos G, Gombakis N, Kontopoulos EE, Tsantali C. Clinical features, laboratory findings and differential diagnosis of benign acute childhood myositis. Acta Paediatr. 2000; 89:1493–4.
crossref
9. Meier PW, Bianchetti MG. An 8-year-old boy with a 4-day history of fever, cough and malaise, and a 2-day history of painful calves and difficulty walking. Eur J Pediatr. 2003; 162:731–2.
crossref
10. Lundberg A. Myalgia cruris epidemica. Acta Paediatr. 1957; 46:18–31.
crossref
11. Middleton PJ, Alexander RM, Szymanski MT. Severe myositis during recovery from influenza. Lancet. 1970; 2:533–5.
crossref
12. Cawkwell GM. Inflammatory myositis in children, including differential diagnosis. Curr Opin Rheumatol. 2000; 12:430–4.
13. Ruff RL, Secrist D. Viral studies in benign acute childhood myositis. Arch Neurol. 1982; 39:261–3.
crossref
14. Koliou M, Hadjiloizou S, Ourani S, Demosthenous A, Hadjidemetriou A. A case of benign acute childhood myositis associated with influenza A (H1N1) virus infection. Clin Microbiol Infect. 2010; 16:193–5.
15. Karpathios T, Kostaki M, Drakonaki S, Garoufi A, Siahanidou S, Spirou N, et al. An epidemic with influenza B virus causing benign acute myositis in ten boys and two girls. Eur J Pediatr. 1995; 154:334–6.
crossref
16. Kratochvil-Stava AJ, Haynatzki GR, Varman M. Retrospective review of influenza-associated acute myositis at a regional children's hospital. Infect Dis Clin Pract (Baltim Md). 2010; 18:183–7.
crossref
17. Agyeman P, Duppenthaler A, Heininger U, Aebi C. Influenza-associated myositis in children. Infection. 2004; 32:199–203.
crossref
18. Kawarai T, Nishimura H, Taniguchi K, Saji N, Shimizu H, Tadano M, et al. Magnetic resonance imaging of biceps femoris muscles in benign acute childhood myositis. Arch Neurol. 2007; 64:1200–1.
crossref
19. Panghaal V, Ortiz-Romero S, Lovinsky S, Levin TL. Benign acute childhood myositis: an unusual cause of calf pain. Pediatr Radiol. 2008; 38:703–5.
crossref
20. Watanabe T, Yoshikawa H, Abe Y, Yamazaki S, Uehara Y, Abe T. Renal involvement in children with influenza A virus infection. Pediatr Nephrol. 2003; 18:541–4.
crossref
21. Heiner JD, Ball VL. A child with benign acute childhood myositis after influenza. J Emerg Med. 2010; 39:316–9.
crossref

Table. 1
Characteristics of the Study Population (n=16)
Variable Value
Gender (M/F) 12/4 (75/25)
Age (yr) 4.6 1.1 (3 ± −7)
Time (day) 3.6 1.5 (1 ± −7)
Duration (day) 2.6 1.0 (1 ± −4)
Hospital stay (day) 5.0 1.0 (4 ± −7)

Values are presented as number (%) or mean SD ± (range).

Between onset of influenza and onset of influenza B-

From onset of influenza B-asso-associated myositis. ciated myositis to clinical recovery.

Table.
2. Clinical Manifestations of Influenza B-Associated Myositis in Children (n=16)
Symptom/sign No. of patients (%)
Calf pain 16 (100)
Cough 12 (75)
Fever 9 (56)
Sore throat 4 (25)
Headache 1 (6)
Table.
3. Laboratory Findings on Admission
Variable Value
Hemoglobin, g/dL 12.5 0.8 ±
  (11.4–13.5)
White blood cell count, 10 × 9/L 5.4 2.4 ±
  (2.7–9.7)
Platelet count, 10 × 9/L 179 43 ±
  (116–273)
C-reactive protein, mg/L 9.7 16.0 ±
  (0.1–53.6)
Creatine phosphokinase, U/L 2,366 2,479 ±
  (62–7,649)
Aspartate aminotransferase, U/L 105 88 ±
  (33–323)
Alanine transaminase, U/L 31 22 ±
  (10–86)
Lactate dehydrogenase, U/L 686 249 ±
  (471–1,316)
Creatinine, mg/dL 0.4 0.1 ±
  (0.2–0.5)

Values are presented as mean SD (range). ±

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