Rashes

Key Conditions

Core 1 (Pre-Clerkship)
- Biomedical Science
  - Microbiology I
    - Gram Positives Part 1: Intro and Streptococci
      - Newborn infections, scarlet fever
    - Gram Positives Part 2: Staphylococci
      - Toxin-mediated diseases including SSSS, TSS
    - Parasitology
      - TORCH infections
    - Vector-borne diseases
      - Lyme, RMSF
    - Herpesvirus
      - HSV 1 and 2, VZV, CMV
    - Childhood Viral Infections
      - Measles, rubella, parvovirus
  - Microbiology II
    - Infection Syndromes
      - Infections originating in the skin, viral exanthems, infection-related rashes
    - Viruses/Anti-virals
      - Perinatally acquired infections
- Integrative Systems
  - Dermatology
    - Intro to Dermr
    - Skin of Color
    - Urticaria
    - Infestations
    - Fungal diseases
    - Bacterial diseases
    - HSV, VZV, and enterovirus,
    - Syphilis
    - Psoriasis and other scaley rashes
    - Atropic dermatitis
    - Allergic contact dermatitis
    - Autoimmune connective tissue disease
    - Acne
    - Petechiae, purpura, and vasculitis
    - Immunobullous diseases
    - Pediatric derm
    - Viral exanthems
    - Drug reactions
Core 2 (Clerkship)
- Pediatric Clerkship Didactics on Fevers
Core 3 (Post-Clerkship)
- Electives that may further knowledge: Pediatric dermatology elective, Dermatology elective

STEP 1: Sick or not sick?

├── Sick → Immediate treatment; rash may offer clues but don’t delay care

└── Not Sick → Proceed to Step 2

↓

STEP 2: Evidence of serious systemic illness?

├── YES:

│ - Petechiae, Purpura → Consider ITP, Meningococcemia, HSP, abuse, etc.

│ - Vesicles, Bullae → Consider HSV, chickenpox, burns, etc.

│ - Target lesions → Think EM, SJS/TEN, rheumatic fever

│ - Urticaria or Desquamation → Evaluate for anaphylaxis, Kawasaki, etc.

└── NO → Proceed to Step 3

↓

STEP 3: Mucous membrane involvement?

├── Concerning signs? (e.g., Koplik spots, wet purpura)

└── Not significant → Step 4

↓

STEP 4: Classic pediatric rash?

├── YES → Diagnose accordingly (e.g., impetigo, HFM, molluscum, eczema)

└── NO or unclear → Proceed to Step 5

↓

STEP 5: Not sure?

├── Admit diagnostic uncertainty

├── Reassure if no concerning features

├── Provide anticipatory guidance

├── Encourage follow-up in 12–24 hours

└── Consider expert consultation (e.g., Dermatology, Rheumatology, ID)

Rash characteristics
- Duration: How long has the rash been present?
- Initial appearance: How did the rash look when it first appeared?
- Location: Where did it first appear?
- Evolution: How has the rash changed over time?
Associated symptoms
- Fever
- Pruritus
- Pain
Any treatments that have been used? Alleviating or exacerbating factors?
- Other relevant medical history
- Household contacts with similar rash?
- New medications, products, animal, or environmental exposures?
- Recent travel? Recent illnesses?
- Chronic medical conditions?
- Family history of skin or autoimmune disorders?
- Allergies? Pets?
- Up to date on routine immunizations?
- Sexual risk factors?

Arrangement
- Linear: allergic contact dermatitis due to plants (e.g, poison ivy), lichen striatus, incontinentia pigmenti
- Grouped: herpes simplex virus infection, warts, molluscum contagiosum, microcystic lymphatic malformation
- Dermatomal: herpes zoster
- Annular (ie, ring-shaped with central clearing): tinea corporis, granuloma annulare, erythema migrans, lupus erythematosus

Color
- Erythematous: pink or red, blanching or non-blanching
- Hyperpigmented: tan, brown, or black
- Hypopigmented: amount of pigment decreased but not entirely absent (e.g., post-inflammatory pigmentary alteration)
- Depigmented: all pigment absent (e.g., vitiligo)