Differential Diagnosis for Severe Bilateral Calf Pain in a 12-year-old Boy
- Single most likely diagnosis
- B) Influenza-induced myositis: This condition is characterized by muscle pain, particularly in the calves, following a viral infection such as influenza. The boy's recent history of a dry cough, sore throat, headache, and fever, which are common symptoms of influenza, followed by severe bilateral calf pain, makes this diagnosis the most likely.
- Other Likely diagnoses
- D) Parvovirus B19-induced arthritis: Although more commonly associated with arthritis, Parvovirus B19 infections can sometimes present with myalgias. The recent viral illness could be consistent with Parvovirus B19, but the primary complaint of calf pain rather than joint pain makes this less likely than influenza-induced myositis.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- E) Rheumatic fever: This is a serious complication of untreated streptococcal infections, characterized by symptoms including joint pain, fever, and sometimes abdominal pain. Although the boy's symptoms do not strongly suggest rheumatic fever, missing this diagnosis could have severe consequences, including heart damage.
- C) Mucocutaneous lymph node syndrome (Kawasaki disease): While Kawasaki disease primarily presents with fever, rash, conjunctivitis, and lymphadenopathy, it can also involve musculoskeletal symptoms. Given its potential for serious cardiac complications, it should be considered in the differential diagnosis of any child with recent fever and current musculoskeletal symptoms.
- Rare diagnoses
- A) Dermatomyositis: This is an inflammatory disease characterized by skin rash and muscle weakness. It is rare in children and would typically present with more systemic symptoms and specific skin findings, which are not mentioned in the scenario. The lack of skin involvement and the acute onset of symptoms make this a less likely diagnosis.