Fever & Rash

Question 1

MACULOPAPULAR RASH DDx

Answer 1

Viral

• Measles (Rubeola)
• Rubella (German measles)
• Erythema infectiosum (Parvovirus)
• Roseola (exanthema subitum, usually HHV-6)
• Coxsackie viruses
• Syphillis

Noninfectious: Drug eruptions

Question 2

NODULES & PAPULES DDx

Answer 2

• Bacterial abscess
• Fungal
  
  • Cryptococcus
  • Histoplasma
  • Coccidioides
  • Sporotrichosis: rose bush, lymphatic spread
• Atypical
  
  • Nocardia: During gardening or farming; Direct inoculation of organisms into the skin
  • Bartonella
  • Mycobacteria

Question 3

ULCER DDx

Answer 3

• Syphilis (T. pallidum)
• Bacillus anthracis – anthrax
• Francisella tularensis
• Herpes
• Leishmania
• Buruli ulcer – Mycobacteria ulcerans

Question 4

Vesicles

Answer 4

• Herpes
• Varicella zoster
• HSV
• Coxsackie

Question 5

Coxsackie

Answer 5

• Picornavirus (enterovirus)
• General Clinical syndrome:** **Aseptic meningitis; Rash

Coxsackie Type A

• Herpangina: painful palatal ulcers
• Rash may involve palms & soles

Coxsackie Type B

• Myocarditis, cardiomyopathy, arrhythmias
• Pleurodynia
• Burnholm’s disease: devil’s grip -> intense intercostal pain

Question 6

Bullous lesion DDx

Answer 6

• Staphylococcal scalded skin syndrome
• Vibrio vulnificus

Question 7

Vesiculopustular DDx

Answer 7

N. gonorrhea

Disseminated infection

• May not have GU symptoms!
• Arthritis;Tenosynovitis
• Dermatitis

Question 8

VESICULOPUSTULAR

Answer 8

Gonnococcemia

Question 9

PETECHIAE (3 MM) DDx

Answer 9

• Neisseria meningitides:
• RMSF

Question 10

INSECT BITES: Scabies

Answer 10

Sarcoptes scabiei (mite): Severe diseases in immunosupressed individuals

• pruritic
• linear burrows on hands or interdigits

Question 11

NECROTIZING FASCIITIS DDx

Answer 11

2 types: Monomicrobial (“Type 2”) or Polymicrobial (“Type 1”)

1. Monomicrobial (“Flesh-eating bacteria”)

• Group A beta-hemolytic streptococci (GAS)
• Pyrogenic exotoxins act as superantigens and trigger massive cytokine release, causing sepsis and shock
• GAS is susceptible to bacitracin
• Also S. aureus

Warning signs:

• Severe pain
• Violaceous bullae
• Marked edema
• Crepitus, gas in tissue (seen on X-ray)  Systemic toxicity, multiorgan failure
• Rapid spread

2. Polymicrobial

• Gram positive: streptococci
• Gram negative: Enterobacteriaceae, E. coli, Enterobacter, Klebsiella, Proteus
• At least one anaerobe: Bacteroides or Peptostreptococcus

Sx:

• Fournier gangrene of scrotum
• frank necrosis

Question 12

Nocardia

Answer 12

• AFB due to mycolic acid
• Filamentous rod
• Catalase +
• Urease +
• Obligate aerobe
• During gardening or farming; Direct inoculation of organisms into the skin
  
  • non-spore forming
• Affects immunocompromised Pt

Sx:

• Pulm: pneumonia-like sx, assoc w cavitary lesions of lung
• Brain abscess
• Cutaneous: indurated lesions and inflammatory response -> nodules and papules

Question 13

Answer 13

Leishmaniasis

Tissue protozoa

Question 14

Answer 14

Sporotrichosis

Sporothrix schenkii