What is the treatment for a 2-year-old with a red, dry, scaly rash on and under the scrotum?

Treatment for a Red, Dry, Scaly Rash on and Under the Scrotum in a 2-Year-Old

For a 2-year-old with a red, dry, scaly rash on and under the scrotum, topical hydrocortisone cream is the recommended first-line treatment, applied to the affected area up to 3-4 times daily. 1

Differential Diagnosis

Before initiating treatment, it's important to consider the differential diagnosis for scrotal rash in a toddler:

1. Atopic dermatitis - Most likely diagnosis given the dry, scaly, red appearance
2. Contact dermatitis - From diapers, soaps, or other irritants
3. Seborrheic dermatitis - Can overlap with atopic dermatitis in infancy
4. Fungal infection (tinea) - Common in warm, moist areas
5. Acute idiopathic scrotal edema - Usually painless with marked scrotal wall thickening 2

Diagnostic Approach

The diagnosis of atopic dermatitis or contact dermatitis is primarily clinical, based on:

• Appearance of the rash (red, dry, scaly)
• Distribution (on and under scrotum)
• Age of the patient (2 years)
• Absence of other concerning symptoms

Unlike acute scrotal pain which requires urgent evaluation for testicular torsion, a chronic rash without pain or acute onset does not typically warrant emergency imaging or surgical consultation 2.

Treatment Algorithm

1. First-line treatment:

   • Topical hydrocortisone cream (1%) applied 3-4 times daily to affected areas 1
   • Continue for 7-10 days or until improvement

2. Supportive measures:

   • Gentle cleansing with warm water (avoid soaps with fragrances)
   • Pat dry thoroughly after bathing
   • Loose-fitting cotton underwear or allowing "air time" without diapers when possible
   • Petroleum jelly as a moisture barrier after hydrocortisone application

3. If no improvement within 7 days:

   • Consider referral to pediatric dermatology
   • Evaluate for fungal infection (may require antifungal cream)
   • Consider patch testing if contact dermatitis is suspected

Important Considerations

• Avoid over-treatment: Prolonged use of topical corticosteroids on genital skin can lead to skin atrophy or, paradoxically, rebound erythema (red scrotum syndrome) 3

• Rule out infection: If the rash appears pustular or has yellow crusting, consider bacterial infection (impetigo) which would require antibiotic treatment 4

• Differentiate from more serious conditions: Acute scrotal pain, swelling, or sudden onset would require immediate evaluation to rule out testicular torsion or epididymitis 2

Follow-up

• Improvement should be seen within 7 days of treatment
• If the rash persists or worsens despite appropriate treatment, reconsider the diagnosis and refer to a pediatric dermatologist
• For recurrent episodes, consider allergy testing or evaluation for underlying atopic dermatitis

The key to successful management is correct identification of the condition and appropriate use of topical hydrocortisone, while avoiding potential triggers and maintaining good genital hygiene.