What is the appropriate prescription for a patient presenting to the outpatient department with allergic dermatitis?

Treatment of Allergic Dermatitis in the Outpatient Setting

For a patient presenting with allergic dermatitis, prescribe a mid- to high-potency topical corticosteroid (such as triamcinolone 0.1% or clobetasol 0.05%) applied twice daily to affected areas, combined with liberal emollient use and oral antihistamines for symptomatic relief of pruritus. 1

Initial Assessment and Grading

Before prescribing, assess the severity based on body surface area (BSA) involvement and symptom intensity:

• Mild (Grade 1): <10% BSA involvement with minimal symptoms 2
• Moderate (Grade 2): 10-30% BSA involvement with pruritus, burning, or tightness 2
• Severe (Grade 3): >30% BSA with moderate-to-severe symptoms limiting self-care activities 2

Rule out secondary bacterial or viral infection before initiating treatment, as these must be addressed concurrently. 3

First-Line Prescription Regimen

Topical Corticosteroids

For localized mild-to-moderate allergic dermatitis:

• Prescribe triamcinolone 0.1% cream or ointment applied twice daily to affected areas 1
• For face and intertriginous areas, use lower potency options like hydrocortisone 2.5% cream 2

For moderate-to-severe or widespread disease:

• Prescribe clobetasol 0.05% ointment or cream (ultra-high potency) applied twice daily 1
• Limit ultra-high potency steroids to maximum 2 weeks continuous use and ≤50g per week 4
• Ointments are more effective than creams due to superior penetration 5, 6

Emollients

• Prescribe fragrance-free, ointment-based emollients to be applied liberally and frequently, especially immediately after bathing 2, 4
• This restores the epidermal barrier and enhances corticosteroid efficacy 4

Oral Antihistamines

For pruritus control:

• Cetirizine 10 mg once daily or loratadine 10 mg once daily (non-sedating) 2
• Hydroxyzine 10-25 mg four times daily or at bedtime (sedating—reserve for nighttime use only) 2, 4

The sedating antihistamines provide benefit purely through sedation to help patients sleep through severe itching, not through anti-pruritic mechanisms. 4

Treatment Duration and Tapering

• Continue topical corticosteroids until lesions resolve to minimal or no symptoms (typically 2-4 weeks) 2
• Once improved, taper to twice-weekly maintenance application of medium-potency topical corticosteroids to prevent flares 2
• Emollients should be continued indefinitely as maintenance therapy 2, 4

When to Escalate or Refer

Consider systemic corticosteroids if:

• Allergic contact dermatitis involves >20% BSA 1
• Prescribe prednisone 0.5-1 mg/kg/day tapered over 2-3 weeks (not less, to avoid rebound dermatitis) 2, 1

Refer to dermatology if:

• No improvement after 4-6 weeks of appropriate topical therapy 2
• Suspected autoimmune or severe cutaneous adverse drug reaction 2
• Need for patch testing to identify specific allergens 1

Alternative Topical Agents (Second-Line)

If corticosteroid-sparing therapy is needed or for sensitive areas:

• Tacrolimus 0.1% ointment twice daily (adults) 2, 7
• Pimecrolimus 1% cream twice daily (mild-to-moderate disease) 2, 3
• Crisaborole 2% ointment twice daily 2
• Ruxolitinib 1.5% cream twice daily 2

These calcineurin inhibitors and newer agents are particularly useful for facial dermatitis and long-term maintenance without the atrophy risk of corticosteroids. 2, 4

Critical Pitfalls to Avoid

• Do not prescribe topical antihistamines—they provide no benefit and may cause sensitization 2
• Do not withhold topical corticosteroids when infection is present—treat infection with appropriate systemic antibiotics while continuing anti-inflammatory therapy 4
• Avoid rapid discontinuation of systemic steroids—taper over minimum 2-3 weeks to prevent severe rebound dermatitis 1
• Do not use ultra-high potency steroids on face, genitals, or intertriginous areas—these sites have increased absorption and higher risk of atrophy 2, 6
• Address "steroid phobia"—educate patients that appropriate intermittent use of topical corticosteroids is safe and effective 4

Specific Instructions for Patient

• Apply topical corticosteroid to affected areas only, twice daily 1
• Apply emollient immediately after bathing and frequently throughout the day 2, 4
• If using both, apply corticosteroid first, then emollient after 2
• Avoid identified allergens and skin irritants 2
• Minimize sun exposure during active treatment 2
• Return if no improvement in 4-6 weeks or if symptoms worsen 2