Dermatology for AMC MCQ

A 6 year old boy has a long history of an itchy rash in the creases of his elbows and knees, dry and thickened from scratching, that flares and settles. He has asthma and hay fever, and his mother had childhood eczema. There is no weeping, crusting or blistering. His sleep is disturbed by the itch. What is the most likely diagnosis?

1. Eczema herpeticum A painful vesicular eruption complicating eczema, an emergency. Chronic itchy flexural dermatitis with an atopic history and no infection makes it the danger.
2. Scabies Intense itch with burrows and a household contact. Chronic itchy flexural dermatitis with an atopic history and no infection raises it.
3. Atopic dermatitis/eczema correct Correct. Chronic itchy flexural dermatitis with an atopic personal and family history is atopic dermatitis.
4. Psoriasis Well-demarcated plaques with silvery scale on extensor surfaces. Chronic itchy flexural dermatitis with an atopic history and no infection points elsewhere.
5. Cutaneous T-cell lymphoma A persistent atypical dermatitis in an adult. Chronic itchy flexural dermatitis with an atopic history and no infection argues for biopsy where atypical.

The point: Atopic dermatitis is a chronic, relapsing, itchy inflammatory skin condition, usually starting in childhood, with a personal or family history of atopy. It affects the face and extensor surfaces in infants and the flexures in older children and adults, with dry, itchy, red skin that lichenifies with chronic scratching. The cornerstone of management is liberal and frequent emollients to restore the skin barrier, used continuously even when clear, with soap avoided. Topical corticosteroids, chosen by potency to match the site and severity, treat flares, and the common failure is under-treating with a steroid that is too weak or used too briefly. Identify and reduce triggers such as heat, irritants and, in some, specific allergens. Recognise infection: bacterial infection with weeping and crusting needs antibiotics, and eczema herpeticum, a widespread painful vesicular eruption with punched-out erosions from herpes simplex, is an emergency needing aciclovir. Severe or refractory disease is referred for phototherapy or systemic therapy. Reassure that most childhood eczema improves with age.

Source: Therapeutic Guidelines (Australia) — Dermatology: atopic dermatitis Therapeutic Guidelines (Australia) · tier 3, national formulary

A 6 year old boy has a long history of an itchy rash in the creases of his elbows and knees, dry and thickened from scratching, that flares and settles. He has asthma and hay fever, and his mother had childhood eczema. There is no weeping, crusting or blistering. His sleep is disturbed by the itch. What is the most appropriate initial investigation?

1. Swab of infected or non-healing lesions Where infection is suspected. Chronic itchy flexural dermatitis with an atopic history and no infection indicates it.
2. Consider biopsy for an atypical persistent rash Where the diagnosis is unclear. Chronic itchy flexural dermatitis with an atopic history and no infection makes it useful.
3. Recognition of eczema herpeticum Painful monomorphic vesicles and punched-out erosions. Chronic itchy flexural dermatitis with an atopic history and no infection makes it important.
4. Clinical diagnosis from the pattern and atopic history correct Correct. The pattern and atopic history make the clinical diagnosis without tests.
5. Assessment of severity and impact Guides the treatment step. Chronic itchy flexural dermatitis with an atopic history and no infection makes it discriminating.

The point: Atopic dermatitis is a chronic, relapsing, itchy inflammatory skin condition, usually starting in childhood, with a personal or family history of atopy. It affects the face and extensor surfaces in infants and the flexures in older children and adults, with dry, itchy, red skin that lichenifies with chronic scratching. The cornerstone of management is liberal and frequent emollients to restore the skin barrier, used continuously even when clear, with soap avoided. Topical corticosteroids, chosen by potency to match the site and severity, treat flares, and the common failure is under-treating with a steroid that is too weak or used too briefly. Identify and reduce triggers such as heat, irritants and, in some, specific allergens. Recognise infection: bacterial infection with weeping and crusting needs antibiotics, and eczema herpeticum, a widespread painful vesicular eruption with punched-out erosions from herpes simplex, is an emergency needing aciclovir. Severe or refractory disease is referred for phototherapy or systemic therapy. Reassure that most childhood eczema improves with age.

Source: Therapeutic Guidelines (Australia) — Dermatology: atopic dermatitis Therapeutic Guidelines (Australia) · tier 3, national formulary

A 6 year old boy has a long history of an itchy rash in the creases of his elbows and knees, dry and thickened from scratching, that flares and settles. He has asthma and hay fever, and his mother had childhood eczema. There is no weeping, crusting or blistering. His sleep is disturbed by the itch. What is the most appropriate next step in management?

1. Aciclovir for eczema herpeticum The emergency treatment for herpetic infection. Chronic itchy flexural dermatitis with an atopic history and no infection makes it the emergency step.
2. Antibiotics for bacterial infection For weeping, crusted, infected eczema. Chronic itchy flexural dermatitis with an atopic history and no infection makes it targeted.
3. Liberal emollients as the cornerstone correct Correct. Frequent emollients are the cornerstone of management to restore the barrier.
4. Trigger avoidance and soap substitution Reduces irritation. Chronic itchy flexural dermatitis with an atopic history and no infection makes it supportive.
5. Topical corticosteroids matched to site and severity for flares Appropriately potent topical steroids treat his flares, and chronic itchy flexural dermatitis with an atopic history and no infection here points elsewhere.

The point: Atopic dermatitis is a chronic, relapsing, itchy inflammatory skin condition, usually starting in childhood, with a personal or family history of atopy. It affects the face and extensor surfaces in infants and the flexures in older children and adults, with dry, itchy, red skin that lichenifies with chronic scratching. The cornerstone of management is liberal and frequent emollients to restore the skin barrier, used continuously even when clear, with soap avoided. Topical corticosteroids, chosen by potency to match the site and severity, treat flares, and the common failure is under-treating with a steroid that is too weak or used too briefly. Identify and reduce triggers such as heat, irritants and, in some, specific allergens. Recognise infection: bacterial infection with weeping and crusting needs antibiotics, and eczema herpeticum, a widespread painful vesicular eruption with punched-out erosions from herpes simplex, is an emergency needing aciclovir. Severe or refractory disease is referred for phototherapy or systemic therapy. Reassure that most childhood eczema improves with age.

Source: Therapeutic Guidelines (Australia) — Dermatology: atopic dermatitis Therapeutic Guidelines (Australia) · tier 3, national formulary