Differential diagnosis of acquired myopathy — infections
| Specific Features | |
|---|---|
| Virus | Diffuse myalgias |
| Adenovirus | |
| Coxsackie viruses, especially B | Pleural pain (chest muscle myalgias = Bornholm syndrome) |
| ECHO viruses | |
| Dengue virus | |
| Herpes group (cytomegalovirus, Epstein-Barr, herpes simplex, varicella-zoster) | |
| Hepatitis B, A, and C | |
| HIV | PM-like disease can occur at any time during infection. Could be related to antiretroviral therapy |
| HTLV-1 | PM and/or arthritis in Japan, Caribbean, and Africa |
| Influenza A and B | Particularly lower calf involvement |
| Mumps | |
| Parvovirus B19 | |
| Rubella | |
| SARS-coronavirus | |
| West Nile virus | |
| Bacteria | Mainly focal disease |
| Staphylococcus | Pyomyositis; psoas abscesses common |
| Streptococcus | Necrotizing myositis, pyomyositis |
| Gram-negative: enterobacteria including Yersinia, Pseudomonas, Aeromonas, other; anaerobic: Clostridium, Bacteroides, Fusobacterium, Peptostreptococcus, other | Pyomyositis, psoas abscesses are common |
| Usually pyomyositis; psoas abscesses are common; gas gangrene (Clostridial myonecrosis) | |
| Atypical bacteria | Mainly focal disease |
| Bartonella | |
| Borrelia burgdorferi (Lyme disease) | Focal > diffuse myalgias ± myositis; proximal predominance; rarely orbital involvement |
| Francisella tularensis | |
| Leptospira | |
| Mycobacteria, tuberculosis and others | Psoas abscesses are common |
| Mycoplasma pneumoniae | |
| Rickettsia (including Rocky Mountain spotted fever) | |
| Fungi | Mainly pyomyositis |
| Aspergillus | |
| Candida | |
| Cryptococcus | |
| Fusarium | |
| Pneumocystis carinii (jiroveci) | |
| Parasites | Mainly myalgias with eosinophilia; sometimes pyomyositis |
| Cysticercosis | Myalgias, fever, and eosinophilia with calcified cysts; seizures, headache, psychiatric disorders |
| Echinococcus | |
| Microsporidiae, trachipleistophora, pleistophora | |
| Schistosoma | Fever, abdominal pain, headache, diarrhea |
| Spirometra mansonoides (sparganosis) | |
| Toxocara | |
| Toxoplasma | Immunocompromised host (low CD4 count); resembles polymyositis. Lymphadenopathy common |
| Trichinella | Myalgias and eosinophilia (China, Thailand, Mexico, Bolivia, Argentina, ex-USSR, central Europe) |
| Trypanosoma cruzi | Fever, headache, lymphadenopathy, and periorbital swelling (Romana sign) |
HIV: human immunodeficiency virus; PM: polymyositis; HTLV: human T cell lymphotrophic virus; SARS: severe acute respiratory syndrome.