Term
Mycobacterium avium complex (MAC):
M. avium and M. intracellulare
-features
-clinical findings
-treatments |
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Definition
Features:
- non-photochromagens
- water, soil, dust, plants, poultry, domestic and wild animals
- SE & Gulf coast
- resistant to commonly used TB drugs
Clinical findings:
- AIDS patients especially susceptible
- Men: cavitary lung disease, pulmonary nodules, patchy infiltrates in setting of bronchiectasis, extensive lung destruction
- Women: indolently progressing nodular disease w/ bronchiectasis
- Children: Cervical lymphadenitis (60-85%)
- AIDS patients: disseminated infections (usually lung and focal lymphadenitis) w/ abdominal pain, fever, diarrhea
Treatment:
- clarithromycin/Azithromycin + rifampin/rifabutin + ethambutol +/- amakacin &/or clofazimine (severe disease)
- AIDS patients: may add ciprofloxacin, amikacin, and clofazimine |
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Term
M. kansasii
-features
-clinical findings
-treatments |
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Definition
Features:
- photochromagen
- southern states, Midwest, CA
- rarely isolated from soil, natural water supplies
- consistently isolated from tap water in endemic areas
Clinical findings:
- older males, usually tobacco users with COPD, previous TB, pneumoconiosis or bronchiectasis
- most similar to TB
- upper lobe predilection, cavitation in 90% (responds to INH)
Treatment:
- INH + rifampin, ethambutol for 18 months |
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Term
M. abscessus
-features
-clinical findings
-treatments |
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Definition
Features:
- 3rd most common for pulmonary infections in US
Clinical findings:
- Elderly female non-smokers with no history of underlying lung disease (possibly pertussis)
- non-cavitary with nodular infiltrates, bronchiectasis
- closely resembles non-cavitary MAC disease
Treatment:
- clarithromycin for 6 months +/- imipenem and tobramycin for 6 weeks |
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Term
M. scrofulaceum
-features
-clinical findings
-treatments |
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Definition
Features:
- scotochromagen
- found in swamp water
Clinical findings:
- previously healthy children
- cervical lymphadenitis - must be careful to eliminate cat-scratch disease
Treatment:
- surgical excision |
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Term
M. marinum
-features
-clinical findings
-treatments |
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Definition
Features:
- intermediate growth rate (8-14 d)
- photochromagen
- growth at cooler temperatures
- found in fresh and salt water, fish tanks, fish hook injuries
Clinical findings:
- pet store owners, fishermen
- skin and soft tissue infections often on hand
- "fish tank" or "swimming pool" granuloma
- differentiate from sporotrichosis (fungal infection from rose gardening)
- QFT+
Treatment:
- choose 1 of following for 3 months
- Clarithromycin
- Minocycline/Doxycycline
- TMP/SMX
- Rifampin + Ethambutol
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Term
M. fortuitum
-features
-clinical findings
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Definition
Features:
- non pigmented rapid grower
Clinical findings:
- post-surgical patients (breast augmentation)
- wound infections
- catheter-related infections, post-open heart patients with sternal osteomyelitis |
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Term
M. leprae
-features
-clinical findings
-treatments |
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Definition
Features:
- aka Hansen's disease, leprosy
Clinical findings:
- 4 different presentations based on immune reaction used to counteract it
1. Tuberculoid (TT) 2. Borderline Tubercuolid (BT) 3. Borderline lepromatous (BL) 4. Lepromatous (LL)
- not culturable
- hosts are humans and 9-banded armidillos
- tropical warm temperate climates
- India has 64% of reported cases
Treatment:
- Multi-drug treatment for 2 years
- Dapsone (not for G6PD)
- Rifampin
- Clofazimine
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Term
Tuberculoid M. leprae
- clinical findings |
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Definition
Due to a vigorous cell mediated immune response
Few well-defined raised and hypopigmented skin plaques, some sensory loss around patches, few if any bacilli on biopsy |
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Term
Borderline tuberculoid M. leprae
-clinical findings |
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Definition
Most common
More frequent skin lesions that are variable in appearance, "satellite lesions" present
Enlargement of several peripheral nerves --> muscle weakness, sensory impairement, progressive damage |
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Term
Borderline lepromatous M. leprae
-clinical features |
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Definition
Numerous symmetric erythematous macules w/ normal sensation
Widespread nerve involvement |
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Term
Lepromatous M. leprae
- clinical findings |
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Definition
- Absent cell-mediated response
- Generalized bacteremia - severe
- Widespread involvement of skin and other organs
- Diffuse infiltration of dermis --> progressive thickening (Leonine facies)
- Numerous symmetrical macules, papules, nodules
- Peripheral neuropathy leading to secondary infection |
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