Treatment of Large Erythematous Plaque with Itchiness and No Scaling

Initial Assessment and Differential Diagnosis

The American Academy of Dermatology suggests that contact dermatitis is the most likely diagnosis when presenting as a large erythematous plaque without scaling but with pruritus 1
Allergic contact dermatitis requires prior sensitization and appears 24-72 hours after re-exposure, while irritant contact dermatitis occurs immediately in a dose-dependent manner 1
The lack of scaling makes psoriasis less likely, as psoriasis characteristically presents with silvery scale overlying erythematous plaques 2

The National Comprehensive Cancer Network recommends avoiding high-potency corticosteroids on sensitive areas like the face, genitalia, or intertriginous zones where absorption is increased and skin atrophy risk is higher 3, 2
For facial or intertriginous involvement, the American Academy of Dermatology suggests using only low-potency hydrocortisone 1% to prevent skin atrophy 3, 1
The British Association of Dermatologists recommends prescribing cetirizine 10 mg, loratadine 10 mg, or fexofenadine 180 mg daily for symptomatic itch relief 4, 1

The American Academy of Dermatology suggests taking a detailed exposure history including new products, occupational exposures, and recent travel 1
The British Association of Dermatologists recommends discontinuing any suspected causative agents or irritants immediately 4
If the lesion worsens or shows no improvement after 2 weeks of appropriate topical corticosteroid therapy, the American Academy of Dermatology suggests considering alternative diagnoses 6, 5, 1

The American Academy of Dermatology warns against applying potent topical corticosteroids to large body surface areas for extended periods due to systemic absorption risk 2
The National Comprehensive Cancer Network recommends tapering topical steroids gradually rather than stopping abruptly 3
The American Academy of Dermatology suggests switching to a lower-potency agent or less frequent application before complete discontinuation 2

The American Academy of Dermatology recommends referring to dermatology if there is no response to appropriate first-line therapy after 2 weeks 6, 5
The American Academy of Dermatology suggests referring to dermatology if diagnosis remains uncertain despite initial evaluation 1
The American Academy of Dermatology recommends referring to dermatology if systemic symptoms develop (fever, malaise, joint pain) 1
The American Academy of Dermatology suggests referring to dermatology if lesions become painful, persist >48 hours, or suggest vasculitis 1