Dermatology for PLAB 1

A 3 year old boy has itchy dry skin in the elbow and knee creases with excoriation, present since infancy and worse in winter. His mother has asthma. His mother uses a 30 g tube of emollient which lasts about a month, and applies hydrocortisone 1% to the flexures during flares. He sleeps poorly because of the itching. What is the SINGLE most likely diagnosis?

1. Seborrhoeic dermatitis Greasy scale on the scalp, eyebrows and the sides of the nose, and cradle cap in babies. That does not match a 30 g tube of emollient lasting a month in widespread eczema.
2. Psoriasis Clearly-edged, salmon-pink patches with silvery scale on the outer sides of joints and the scalp, and it itches less than eczema. It does not fit a 30 g tube of emollient lasting a month in widespread eczema.
3. Bacterial superinfection of eczema Weeping skin with golden crusting and small pus bumps on top of known eczema. But a 30 g tube of emollient lasting a month in widespread eczema does not point to it.
4. Atopic dermatitis/eczema correct Correct. Itchy skin-fold eczema since he was a baby, with a family history of allergy conditions and a pattern that is worse in winter. The diagnosis is clear. What has gone wrong is the treatment.
5. Scabies Very bad itching that is worse at night, with burrow marks between the fingers and on the wrists, and other people in the house affected too. Here, a 30 g tube of emollient lasting a month in widespread eczema points elsewhere.

The point: Moisturizers (emollients) are the base of eczema treatment. Most people use far less than they need. A child with eczema over their whole body needs about 250 to 500 g a week, and they should keep using it even when the skin looks clear. The strength of the steroid cream depends on where the skin is and how bad the eczema is. Use a mild cream on the face and in the skin folds (flexures). Save the strong cream for thick, hardened skin (called lichenified skin) on the body and arms and legs, and never use it on the face. Put on the steroid cream and the moisturizer about 30 minutes apart, in either order, and use the fingertip unit (the amount that covers an adult fingertip) to measure how much cream to use. Eczema herpeticum is the emergency to watch for. It causes clusters of painful sores with punched-out edges that spread fast, along with fever, and it needs the antiviral drug aciclovir plus a same-day check by a skin doctor. Weeping skin, crusting, and small pus bumps point to a bacterial infection, usually from the germ Staphylococcus aureus (staph).

Source: NICE CG57 — Atopic eczema in under 12s: diagnosis and management NICE · tier 1, national regulator or guidance

A 3 year old boy has itchy dry skin in the elbow and knee creases with excoriation, present since infancy and worse in winter. His mother has asthma. His mother uses a 30 g tube of emollient which lasts about a month, and applies hydrocortisone 1% to the flexures during flares. He sleeps poorly because of the itching. What is the SINGLE most appropriate initial investigation?

1. Patch testing Done for suspected allergic contact dermatitis, in a specialist clinic, and it is not the same test as prick testing for other allergies. It does not fit a 30 g tube of emollient lasting a month in widespread eczema.
2. Skin scrapings for fungal microscopy Done for a ring-shaped scaly patch, especially one that got worse after a steroid cream. That does not match a 30 g tube of emollient lasting a month in widespread eczema.
3. Viral swab for herpes simplex PCR Done when eczema herpeticum is suspected, but treatment starts right away on the doctor's judgment, not once the result comes back. But a 30 g tube of emollient lasting a month in widespread eczema does not point to it.
4. Review the emollient quantity actually being used correct Correct. The single most useful question to ask when a child's eczema will not settle. Stepping up the steroid cream before fixing this treats the wrong problem.
5. Bacterial swab of the weeping area Done when a bacterial infection is suspected, especially if the first treatment has not worked. Here, a 30 g tube of emollient lasting a month in widespread eczema points elsewhere.

The point: Moisturizers (emollients) are the base of eczema treatment. Most people use far less than they need. A child with eczema over their whole body needs about 250 to 500 g a week, and they should keep using it even when the skin looks clear. The strength of the steroid cream depends on where the skin is and how bad the eczema is. Use a mild cream on the face and in the skin folds (flexures). Save the strong cream for thick, hardened skin (called lichenified skin) on the body and arms and legs, and never use it on the face. Put on the steroid cream and the moisturizer about 30 minutes apart, in either order, and use the fingertip unit (the amount that covers an adult fingertip) to measure how much cream to use. Eczema herpeticum is the emergency to watch for. It causes clusters of painful sores with punched-out edges that spread fast, along with fever, and it needs the antiviral drug aciclovir plus a same-day check by a skin doctor. Weeping skin, crusting, and small pus bumps point to a bacterial infection, usually from the germ Staphylococcus aureus (staph).

Source: NICE CG57 — Atopic eczema in under 12s: diagnosis and management NICE · tier 1, national regulator or guidance

A 3 year old boy has itchy dry skin in the elbow and knee creases with excoriation, present since infancy and worse in winter. His mother has asthma. His mother uses a 30 g tube of emollient which lasts about a month, and applies hydrocortisone 1% to the flexures during flares. He sleeps poorly because of the itching. What is the SINGLE most appropriate immediate management?

1. Topical calcineurin inhibitor Tacrolimus or pimecrolimus cream, used instead of a steroid for the face and for spots that keep flaring. It does not fit a 30 g tube of emollient lasting a month in widespread eczema.
2. Generous emollients, 250 to 500 g a week, continued when clear correct Correct. He is getting about a twentieth of what he needs. Enough moisturizer cuts down both the flares and how much steroid cream is needed.
3. Potent topical corticosteroid for the trunk and limbs For thick, hardened eczema on the body, used in short courses, and never put on the face. But a 30 g tube of emollient lasting a month in widespread eczema does not point to it.
4. Topical antifungal, not a steroid For a fungal skin infection (tinea), where a steroid cream would calm the redness but let the fungus spread further. Here, a 30 g tube of emollient lasting a month in widespread eczema points elsewhere.
5. Oral aciclovir and same-day dermatology assessment For eczema herpeticum. If it is near the eyes, an eye doctor (ophthalmologist) must also see the patient the same day. That does not match a 30 g tube of emollient lasting a month in widespread eczema.

The point: Moisturizers (emollients) are the base of eczema treatment. Most people use far less than they need. A child with eczema over their whole body needs about 250 to 500 g a week, and they should keep using it even when the skin looks clear. The strength of the steroid cream depends on where the skin is and how bad the eczema is. Use a mild cream on the face and in the skin folds (flexures). Save the strong cream for thick, hardened skin (called lichenified skin) on the body and arms and legs, and never use it on the face. Put on the steroid cream and the moisturizer about 30 minutes apart, in either order, and use the fingertip unit (the amount that covers an adult fingertip) to measure how much cream to use. Eczema herpeticum is the emergency to watch for. It causes clusters of painful sores with punched-out edges that spread fast, along with fever, and it needs the antiviral drug aciclovir plus a same-day check by a skin doctor. Weeping skin, crusting, and small pus bumps point to a bacterial infection, usually from the germ Staphylococcus aureus (staph).

Source: NICE CG57 — Atopic eczema in under 12s: diagnosis and management NICE · tier 1, national regulator or guidance