PEDIATRIC ID QUIZ

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PEDIATRIC ID QUIZ 1
ENLARGE IMAGE
ENLARGE IMAGE

• CC/HPI 13 year old Caucasian female
  evaluated as outpatient in August for skin
  lesions in the sole of her right foot. Her
  lesions were painless, non-pruritic and began to
  appear one month before her evaluation she
  stated that she had observed a mild yellow
  discharge from some of them.
• Past medical history otitis media when
  she was 2 years old. Varicella at 3 years of age.
• Family history her grandmother suffers
  from emphysema.
• Immunizations up to date
• Social she lives in Mobile, she is a
  basketball player. She enjoys going to the beach,
  and remembers that about 3 weeks before her skin
  lesions developed she suffered a small laceration
  on her right foot while walking over a barnacle
  in Dauphin island.
• Her physical exam is normal except for the
  lesions observed in the pictures.

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ADDITIONAL INFORMATION
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WHICH OF THE FOLLOWING TESTS WOULD YOU OBTAIN?
CBC
SKIN BIOPSY AND CULTURE
VARICELLA DFA
ESR
SPUTUM CULTURE
PPD
SUPERFICIAL SKIN CULTURE
CRP
CXR
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DIAGNOSIS
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PPD 8mm induration
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SKIN BIOPSY NON-CASEATING GRANULOMAS FUNGAL AND
MYCOBACTERIAL CULTURES INCUBATING
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SUPERFICIAL SKIN CULTURE NO GROWTH AFTER 72 HOURS
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• THIS TEST IS NOT NECESSARY

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WHICH ORGANISM IS THE MOST LIKELY ETIOLOGY OF
THIS PATIENTS CONDITION?
Mycobacterium tuberculosis
Sporothrix schenckii
Mycobacterium marinum
Staphylococcus aureus
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Mycobacterium marinum infection

• A culture obtained from tissue when the skin
  biopsy was performed yielded Mycobacterium
  marinum 3 weeks later.
• This patient was prescribed treatment with
  rifampin (300 mg daily) and clarithromycin (250
  mg) BID as soon as infection with Mycobacterium
  marinum was suspected. The initial diagnosis was
  based on history of exposure to a barnacle,
  appearance of the lesions and a positive PPD.
• By the time culture results were available
  she had already received three weeks of therapy
  with these antimicrobials. Her lesions resolved
  after receiving antimicrobial therapy for three
  months.

CLICK HERE TO LEARN MORE ABOUT Mycobacterium
marinum
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Mycobacterium marinum is commonly found in salt
and fresh water. It is the cause of skin
granulomas in patients who have sustained
injuries with contaminated objects such as fish
hooks, barnacles or shells. This condition is
more frequently observed during the summer months
among children living in coastal or estuarine
areas. This condition is also known as fish tank
granuloma due to the association of infection
with history of manipulation of fish tanks. The
diagnosis at presentation is mainly clinical and
based on history of exposure and the typical
bluish appearance of the skin lesions. The
tuberculin skin test among patients with this
condition is usually positive and between 5 and
10 mm of induration. A skin biopsy with culture
can be performed for confirmation. Finding on
skin biopsy may include mixed inflammation, the
presence of non-caseating granulomas and acid
fast bacilli. Confirmation is performed by
culture in media such as Middlebrook agar. The
differential diagnosis of infection with
M.marinum includes infections with other atypical
mycobacteria and fungal organisms such as
Sporotrichosis. Although this infection may be
self limited, treatment with antimicrobials such
as rifampin, ethambutol and clarithromycin is
indicated when spontaneous resolution does not
occur or when more lesions develop. Most lesions
resolve after several weeks of treatment with
antimicrobials. In severe presentations surgical
removal of the lesions may be indicated. Invasive
infection with M. marinum occurs but it is not
common.
CLICK HERE TO VIEW THE REFERENCES AND LINK TO THE
WEB
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REFERENCES

• Jaffer S. Mycobacterium marinum infection of the
  skin. eMedicine 2002. View reference
• Lahey T. Invasive Mycobacterium marinum
  infections. EIN 2003 111496-1498. View
  reference
• Aubry A et al. Sixty three cases of Mycobacterium
  marinum infection clinical features, treatment,
  and antibiotic susceptibility of causative
  isolates. Arch Intern Med 20021621746-52 View
  reference
• Lewis FM, March BJ, von Reyn CF. Fish tank
  exposure and cutaneous infections due to
  Mycobacterium marinum tuberculin skin testing,
  treatment and prevention. Clin Infect Dis 2003
  37 390-7 View reference

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  completed this activity
• Check your e-mail frequently for Pediatric ID
  QUIZ
• If you have any questions about this or any
  other cases feel free to contact me by e-mail at
  bestrada_at_usouthal.edu or you may page me at
• 582-0072
• This activity has been supported by the
  Mitchell Clinical Scholars Program
• Benjamin Estrada MD
• Associate Professor of Pediatrics
• Division of Pediatric Infectious Diseases
• University of South Alabama