Rashes


Blistering Rash

Rapid Review

  • Febrile
    • Varicella
    • Hand-foot-and-mouth disease
    • Necrotizing fasciitis
    • Disseminated gonococcal disease
    • Purpura fulminans
    • Disseminated intravascular coagulopathy (DIC)
    • Staph Scalded Skin Syndrome (SSSS)
    • Toxic Epidermal Necrolysis (TEN)
  • Afebrile
    • Bullous pemphigoid
    • Pemphigus vulgaris
    • Contact dermatitis
    • Herpes zoster
    • Dyshidrotic eczema
    • Burns
  • History
    • Recent new medications
    • Rapid vs gradual onset
  • Physical Exam
    • Diffuse or localized
      • Localized suggests contact dermatitis, herpes zoster, eczema, or coxsackie virus
    • Abnormal Vitals (tachycardia, hypotension)
      • Consider meningitis, DIC, endocarditis
    • Palpable vs Non-palpable
      • Non-palpable suggests thrombocytopenia or DIC
    • Positive Nikolsky sign
      • Consider pemphigus vulgaris, SSSS, TEN
  • Work-up
    • Labs
      • CBC, BMP, blood/urine cultures
      • Skin biopsy
        • If suspect SJS/TEN
      • PCR of DNA of vesicular fluid
        • If suspect varicella-zoster

Pearls

Video Credit: Paul Bolin


Erythematous Rash

Rapid Review

  • Differentials
    • Positive Nikolsky sign
      • Staph Scalded Skin Syndrome
      • Toxic Epidermal Necrolysis
    • Negative Nikolsky sign
      • Drug reaction w/ eosinophilia and systemic symptoms (DRESS)
      • Kawasaki
      • Scarlet fever
      • Anaphylaxis
      • Angioedema
      • Scombroid
  • History
    • Fever/chills
    • Recent new food/drug exposure
    • History of allergies
  • Physical Exam
    • Nikolsky sign
      • Narrows differential (see above)
    • Mucosal involvement
      • Consider angioedema, Kawasaki
  • Work-up
    • CBC, BMP,
    • Skin biopsy
      • If suspect EM/SJS/TEN

Pearls

Video Credit: Medical Minutes


Maculopapular Rash

Rapid Review

  • Differentials
    • Central distribution
      • Viral exanthem
      • Lyme disease
      • Drug reaction
      • Pityriasis
    • Peripheral distribution
      • Steven Johnson Syndrome (SJS)
      • Erythema multiforme
      • Meningococcemia
      • Rocky mountain spotted fever
      • Syphilis
      • Lyme disease
      • Scabies
      • Eczema
      • Psoriasis
  • History
    • Fever/chills
    • Outdoor exposures
    • Recent viral infection
    • Recent new medication
  • Physical Exam
    • Central vs Peripheral
      • Narrow differentials
    • Targetoid
      • Suggests erythema multiforme or lyme disease
    • Scaling
      • Consider scabies, tinea, psoriasis
  • Work-up
    • CBC, BMP,
    • Skin biopsy
      • If suspect EM/SJS/TEN
    • Serologic testing for Lyme

Pearls

Deep Dive

Video Credit: Clinical Pediatric Lectures


Petechial Rash

Rapid Review

  • Differentials
    • Febrile
      • Meningococcemia
      • Disseminated gonococcal infection
      • Henoch-Schlonein purpura
      • Rocky mountain spotted fever
      • Endocarditis
      • Disseminated intravascular coagulopathy (DIC)
      • Thrombotic Thrombocytopenic Purpura (TTP)
      • Hemolytic Uremic Syndrome (HUS)
    • Afebrile
      • Autoimmune vasculitis
      • Idiopathic thrombocytopenic purpura (ITP)
  • History
    • Fever
    • Food exposure
    • Recent vaccines
    • Chronic illness
  • Physical Exam
    • Abnormal Vitals (tachycardia, hypotension)
      • Consider meningitis, DIC, endocarditis
    • Palpable vs Non-palpable
      • Non-palpable suggests thrombocytopenia or DIC
  • Work-up
    • Labs
      • CBC, Coagulation studies, D-dimer, fibrinogen level, CMP, blood cultures (if febrile/toxic)

Pearls

Deep Dive

Video Credit: Clinical Problem Solvers
Brandon Simpson, PA-C
Latest posts by Brandon Simpson, PA-C (see all)
  • Blog - 25 Feb 2021