Tuberculous pyomyositis: a re-emerging entity of many faces

Abstract

Tuberculosis (TB) has become a global concern due to its increasing incidence, particularly in immunocompromised patients, closely following the migratory patterns of populations. TB pyomyositis is a rare extrapulmonary manifestation of TB. Its clinical presentation varies and requires a high degree of suspicion for early diagnosis. We present three patients diagnosed with TB pyomyositis: a 46-year-old man with dermatomyositis (DM) and hepatitis B who presented with fever, muscle weakness, and an abscess at the right proximal arm; a 71-year-old immunocompetent male, with a past medical history of tuberculous lymphadenopathy in childhood, who presented with a 2-month history of fever and pain at the right thigh, and a 44-year-old woman with systemic lupus erythematosus (SLE) on prednisone and methotrexate who presented with skin eruption at her thighs mimicking lupus panniculitis. In all three patients, Mycobacterium tuberculosis was identified as the causative agent. The lack of specific signs, the false negative tuberculin skin test in some cases, and the unfamiliarity of many clinicians with this entity can cause diagnostic delays. Prompt diagnosis requires a high index of suspicion especially in immunocompromised patients with fever.

Pyomyositis in a patient with systemic lupus erythaematosus and a review of the literature

“…CT and MRI commonly confirmed the US results and showed one or more collections with or without adjacent muscular swelling, stranding of subcutaneous fat and skin thickening; this was true in all but four cases 14 18 21 25. Of these cases, 13.0% were invasive (n=3),14 18 21 78.3% were suppurative (n=18)4–10 12 13 15 17 19 20 22–25 and 8.7% were late stage PM (n=2) 11 16.…”

“…Of these cases, 13.0% were invasive (n=3),14 18 21 78.3% were suppurative (n=18)4–10 12 13 15 17 19 20 22–25 and 8.7% were late stage PM (n=2) 11 16. At least 47.8% (n=11/23) met the criteria for sepsis,4 5 11 15 16 19 21 22 24 25 and bacteraemia was evident in 7 of 13 documented blood culture results 5 6 16 17 21 22 24…”

“…The diagnosis is therefore frequently missed or delayed as a result of a lack of specific signs and symptoms, a lack of awareness of the disease, atypical manifestations and a varied range of differential diagnoses 17. In certain cases, sciatica,5 deep vein thrombosis,6 fasciitis,7 aseptic necrosis of the femoral head,9 recurrent cellulitis,14 inflammatory myositis,21 or fever with nodular lesions25 is diagnosed prior to a PM diagnosis. In many cases, the invasive stage is prolonged in mycobacterial infections14 21 25 but shortened in non-mycobacterial infections 15–17 22 24.…”

“…In certain cases, sciatica,5 deep vein thrombosis,6 fasciitis,7 aseptic necrosis of the femoral head,9 recurrent cellulitis,14 inflammatory myositis,21 or fever with nodular lesions25 is diagnosed prior to a PM diagnosis. In many cases, the invasive stage is prolonged in mycobacterial infections14 21 25 but shortened in non-mycobacterial infections 15–17 22 24. A lupus flare-up, which sometimes precedes or is accompanied by muscle tenderness and requires intense immunosuppressive therapy, can complicate the treatment of PM or even cause death 13.…”

Piomiositis tuberculosa en un paciente inmunodeprimido

“…Otras condiciones que se asocian a abscesos musculares tuberculosos son el uso crónico de corticoides, la medicación inmunosupresora (metrotexato-azatioprina), el tratamiento con infliximab, las afecciones crónicas (fibrosis pulmonar, sarcoidosis, dermatomiositis, polimiositis, artritis reumatoidea y lupus eritematoso sistémico) y el trasplante renal (13)(14)(15)(16). Existen reportes en pacientes inmunocompetentes (17,18) que ratifican que no siempre la manifestación es insidiosa y larvada, y se han observado casos de sepsis y muerte a causa de la infección, pero también, de la toxicidad de los medicamentos.…”