What treatment is recommended for an adult or child with redness and itchiness in the forearm, possibly with a history of eczema or psoriasis?

Treatment of Redness and Itchiness on the Forearm

For redness and itchiness on the forearm in adults or children, start with liberal emollient application multiple times daily plus a medium-potency topical corticosteroid (such as betamethasone valerate 0.1% or fluticasone propionate 0.05%) applied once or twice daily to affected areas until symptoms resolve, typically within 2-4 weeks. 1, 2

Initial Assessment and Red Flags

Before initiating treatment, quickly assess for complications requiring urgent intervention:

• Check for eczema herpeticum: Look for multiple uniform "punched-out" erosions or vesiculopustular eruptions that are very similar in shape and size. If present, start systemic acyclovir immediately plus empirical antibiotics for secondary bacterial infection. 2, 3
• Evaluate for bacterial superinfection: Extensive crusting, weeping, or honey-colored discharge indicates Staphylococcus aureus infection requiring flucloxacillin. 2
• Rule out contact dermatitis: Deterioration in previously stable eczema may indicate development of allergic contact dermatitis. 1

First-Line Treatment Algorithm

Step 1: Emollient Therapy (Foundation of Treatment)

• Apply emollients liberally and frequently, at least twice daily, to all affected areas and ideally after bathing. 2, 4
• Use emollients as soap substitutes instead of regular soaps, as these remove natural lipids and worsen dry skin. 2
• Continue emollient use even when inflammation is controlled, as this is essential for barrier repair. 1, 4

Step 2: Topical Corticosteroid Selection

For forearm involvement (trunk/extremity location):

• Medium-potency topical corticosteroids are the appropriate starting point for most cases (e.g., betamethasone valerate 0.1%, fluticasone propionate 0.05%, or clobetasone butyrate). 1, 2
• Apply once daily or twice daily—once daily application is probably sufficient for potent topical corticosteroids and results in similar effectiveness to twice daily use. 1, 5
• Continue until signs and symptoms (itching, rash, redness) resolve, typically 2-4 weeks. 1, 2

Potency escalation if needed:

• If moderate-potency steroids fail after 1-2 weeks, escalate to potent topical corticosteroids (e.g., betamethasone dipropionate 0.05%), which result in a large increase in treatment success (70% versus 39% for mild potency). 1, 5
• Reserve very high-potency topical corticosteroids (clobetasol propionate, fluocinonide) for severe flares only, limiting use to 2 weeks maximum. 1

Step 3: Application Technique

• Apply topical corticosteroids to affected skin only, not to normal surrounding skin. 1, 6
• Use the smallest amount needed to control symptoms—a thin layer is sufficient. 2, 6
• If using both emollient and topical corticosteroid, apply the topical corticosteroid first, then emollient after. 2
• Avoid bathing, showering, or swimming immediately after application to prevent washing off the medication. 6

Maintenance Therapy to Prevent Relapse

Once initial control is achieved:

• Implement weekend (proactive) therapy: Apply medium-potency topical corticosteroids (such as fluticasone propionate 0.05%) once daily on 2 consecutive days per week (e.g., Saturday and Sunday) to previously affected areas. 1
• This approach results in a large decrease in relapse likelihood from 58% to 25% (RR 0.43,95% CI 0.32-0.57). 5
• Continue daily emollient use throughout. 1, 4

Special Considerations for Children

• Children under 2 years: Do not use topical calcineurin inhibitors (pimecrolimus, tacrolimus). 6
• All pediatric patients: Use caution with high-potency or ultra-high-potency topical corticosteroids due to risk of hypothalamic-pituitary-adrenal axis suppression, especially in children 0-6 years with high body surface area-to-volume ratio. 1
• Avoid abrupt discontinuation of high-potency corticosteroids without transitioning to appropriate alternative treatment, as this causes rebound flare. 1, 2

Alternative for Sensitive Areas

If the forearm involvement extends to flexural areas (antecubital fossa):

• Consider tacrolimus 0.1% ointment as an alternative to topical corticosteroids for these areas, though this is off-label use. 1
• Tacrolimus has a favorable safety profile with low rates of skin atrophy compared to topical corticosteroids. 1

When to Reassess or Refer

• Reassess in 1-2 weeks if no improvement occurs with initial therapy. 2
• Refer to dermatology if: symptoms fail to respond to medium-potency topical corticosteroids after appropriate trial, diagnostic uncertainty exists, or symptoms persist beyond 6 weeks. 1, 2

Common Pitfalls to Avoid

• Do not use topical corticosteroids continuously long-term without breaks—this increases risk of adverse effects including skin atrophy and hypothalamic-pituitary-adrenal axis suppression. 1, 6
• Do not minimize periocular steroid use if treating areas near the eyes, as association with cataracts or glaucoma is unclear but concerning. 1
• Do not prescribe non-sedating antihistamines for itch control in eczema, as they have little to no value; reserve sedating antihistamines for severe pruritus during relapses, particularly at night. 2
• Do not assume dietary restriction will help—it is of little or no benefit in adults and worth trying only in selected infants under professional supervision. 1, 4
• Do not cover treated areas with bandages, dressings, or wraps unless specifically instructed; normal clothing is acceptable. 6

Sun Protection During Treatment

• Limit sun exposure during treatment, even when medication is not on the skin. 6
• If outdoor exposure is necessary, wear loose-fitting clothing that protects treated areas. 6
• Avoid sun lamps, tanning beds, or ultraviolet light therapy during treatment. 6

Evidence Quality Note

The recommendation for medium-potency topical corticosteroids as first-line treatment is supported by high-certainty evidence from the 2023 American Academy of Dermatology guidelines, which strongly recommend topical corticosteroids for atopic dermatitis based on overwhelming literature. 1 The once-daily versus twice-daily application equivalence is supported by moderate-certainty evidence from a 2022 Cochrane review. 5