Originally published at Pediatric EM Morsels on October 16, 2015. Reposted with permission.

Follow Dr. Sean M. Fox on twitter @PedEMMorsels

“Rash” seems to be a ubiquitous complaint some days in the Ped ED.  Knowing that the skin is the largest organ, it seems only appropriate that we should take these complaints seriously. Unfortunately, often I feel a little inadequate when trying to decipher the code of the Pediatric Rash.  Below is a simple approach I use to help ensure I don’t over-diagnose viral exanthem.

Pediatric Rash Step 1: Sick or Not Sick

• This speaks for itself.
• Sick? 
  • Treat aggressively!
  • The skin findings may help clue you in to the source of the sickness, but don’t let pontification of the unusual rash delay your rapid administration of necessary care!
• Not Sick?
  • Don’t be cavalier, just yet!
  • Not appearing sick is reassuring, but kids can be deceptive!
  • Remain vigilant and move to Step 2.

Pediatric Rash Step 2: Evidence of Badness?

• Naturally, our default is always to be concerned for badness and, thus, we need tolook for evidence of serious, systemic illness first.
• Finding any of the following characteristics does not necessarily define “badness” as being present, but it should make you think more carefully of that possibility.
• Actively look for:
  • Petechiae
    • Is this ITP?
    • Are these petechiae associated with coughing/vomiting and above the nipple line or are they below the nipple line and concerning forMeningococcemia?
  • Purpura
    • Does this fit the “illness script” of HSP?
    • Platelet disorders? TTP?
    • DIC?
    • Unfortunately, must also consider Abuse.
  • Vesicles
    • HSV
    • Chickenpox (yes, it is still around)
  • Bullae
    • Burns to Bullous Impetigo. Lots to consider.
  • Target Lesions
    • Erythema Multiforme?
    • Spectrum of Stevens Johnson Syndrome / Toxic Epidermal Necrolysis?
    • Erythema Marginatum concerning for Rheumatic Fever?
  • Urticaria
    • Is this anaphylaxis?
    • Is it serum sickness?
  • Desquamation
    • Sloughing your skin is generally not good.
    • Staph Scalded Skin Syndrome? Kawasaki Disease?

• If none of these characteristics exist, move to Step 3.

Pediatric Rash Step 3: Look at the Mucous Membranes Again!

• Let’s be honest, looking in a kid’s mouth can be challenging, but this step is very important!
  • For instance, ITP with Wet Purpura (mucous membrane involvement) may be a clue to greater risk of spontaneous bleeding.
  • Certainly, finding Koplick’s Spots would alter your plans.
  • Even finding herpangina or gingivostomatits may impact your plan!

• While wiping the sweat off of your brow and allowing the parent’s muscle fatigue to resolve, move onward to step 4.

Pediatric Rash Step 4: Look for “Common Pediatric Rashes”

• Now, you get to demonstrate your Pediatric Rash Prowess by looking for those “classic” pediatric skin eruptions.
  • Molluscum
  • Pityriasis Rosea
  • Erythema infectiosum
  • Perianal Strep
  • Impetigo and Bullous Impetigo
  • Intertrigo
  • Atopic Dermatitis
  • Scarlatiniform
  • Popsicle Panniculitis
  • Hand-Foot-Mouth Disease
  • Scabies
  • Diaper Dermatitis and Fungal Infection?

• If Steps 1-4 have not lead to a diagnosis or a high level of concern, then move onward to step 5.

Pediatric Rash Step 5: Admit You Aren’t Sure

• This is the hardest part… admitting to the family that you are not sure what the cause of the rash is can be challenging.
• We are not admitting defeat… we are appropriately avoiding the addition of an incorrect “label” (diagnosis) to the patient.
  • Announce your reassurance in the lack of the concerning characteristics…
  • Acknowledge that rashes often evolve over time…
    • In the next several hours to days, your ability to make a more accurate diagnosis may change.
    • Give good anticipatory guidance on what specific things they need to monitor for and encourage repeat evaluation in the next 12-24 hours.

References