Tuberculosis (TB) Differential Diagnoses

Updated: Nov 09, 2017
  • Author: Thomas E Herchline, MD; Chief Editor: Michael Stuart Bronze, MD  more...
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DDx

Diagnostic Considerations

Tuberculosis (TB) is well known for its ability to masquerade as other infectious and disease processes. For example, congenital TB can mimic congenital syphilis or cytomegalovirus (CMV) infection. Along with the differentials listed in the next section, conditions with a presentation that may resemble pulmonary TB include the following:

  • Blastomycosis
  • Tularemia
  • Actinomycosis
  • Mycobacterium avium-intracellulare infection
  • M chelonae infection
  • M fortuitum infection
  • M gordonae infection
  • M kansasii infection
  • M marinum infection
  • M xenopi infection
  • Squamous cell carcinoma

Conditions to be included in the differential diagnosis of extrapulmonary TB include the following:

  • Blastomycosis
  • Tularemia
  • Actinomycosis
  • Hidradenitis suppurativa
  • Eosinophilic granuloma
  • M avium-intracellulare infection
  • M chelonae infection
  • M fortuitum infection
  • M gordonae infection
  • M kansasii infection
  • M marinum infection
  • M xenopi infection
  • Endemic syphilis
  • Erythema induratum (nodular vasculitis)
  • Erythema nodosum
  • Leishmaniasis
  • Leprosy
  • Cat scratch disease
  • Syphilis
  • Syringoma
  • Rheumatoid arthritis

Dermatologic differential diagnosis

Diagnosis of skin infection with M tuberculosis involves the following:

  • Differentiate primary-inoculation TB from ulceroglandular complexes and mycobacterioses
  • Differentiate TB verrucosa cutis from diseases such as North American blastomycosis, chromoblastomycosis, iododerma and bromoderma, chronic vegetative pyoderma, verruca vulgaris, verrucous carcinoma, verrucous atypical mycobacterial infection, and verrucous lupus vulgaris
  • Differentiate miliary TB of the skin (which appears as small, noncharacteristic, erythematous, papular or purpuric lesions) from drug reactions
  • Differentiate scrofuloderma from suppurative lymphadenitis with sinus-tract formation, such as blastomycosis or coccidioidomycosis
  • Differentiate TB cutis orificialis from glossitis, apotheosis, and deep fungal infections
  • Differentiate lupus vulgaris from lupoid rosacea, deep fungal or atypical mycobacterial infection, chronic granulomatous disease, granulomatous rosacea, and Wegener granulomatosis
  • Differentiate erythema induratum from nodular panniculitides (eg, Weber-Christian disease) and nodular vasculitides (eg, syphilitic gumma, nodular pernio)
  • Differentiate papulonecrotic tuberculid from other papulonecrotic entities, such as leukocytoclastic vasculitis, lymphomatoid papulosis, papular eczema, and prurigo simplex with neurotic excoriation
  • Differentiate lichen scrofulosorum from keratosis spinulosa, lichenoid sarcoid, and lichenoid secondary syphilis

Differential Diagnoses