What should I check to distinguish eczema or another itchy rash from a

Assess the skin before attributing the scratches to a sleep disorder: secondary excoriations can obscure the original rash, and itch may be more intense at night NICE CKS.

• Establish the itch–rash sequence: ask about daytime itch, location, onset, severity, duration, evening/night-time worsening, and what the skin looked like before scratching started NICE CKS. Ask about relieving factors and response to emollients or previous topical treatment, and use an itch diary to clarify the pattern NICE CKS.
• Examine beyond the facial scratches: inspect the remaining skin for primary lesions, dryness or scaling, signs of infestation, and dermographism rather than relying on excoriations alone NICE CKS. Look for an exposure-related eczematous rash suggesting contact dermatitis, greasy scale around the scalp, eyebrows or nasolabial folds suggesting seborrhoeic dermatitis, or an annular lesion with central clearing suggesting fungal infection NICE CKS. Ask whether household members have a recently developed itchy rash, which supports considering scabies NICE CKS.
• Obtain an eyewitness description of the sleep episode: ask the caregiver to describe exactly what happens, its timing after sleep onset, frequency, whether movements extend beyond scratching, and the child's awareness and next-morning recollection; collateral observation and timing were central diagnostic clues in reported amnestic nocturnal behaviours Unknown 2026. Clarify whether there is kicking, flailing, shouting or falling from bed, as these accompanied abnormal sleep behaviour in the supplied adult case report Unknown 2026.
• Review medication and exposure timing: record prescribed, over-the-counter and herbal products, and whether symptoms followed a new medicine or dose change NICE CKS. The supplied literature reports amnestic nocturnal eating after zolpidem initiation and abnormal sleep movements after fluoxetine initiation, with improvement after withdrawal, supporting careful assessment of temporal associations Unknown 2026.

Interpret the findings together: a primary rash, itch outside sleep, relevant topical exposures or affected household contacts favours investigating a cutaneous cause, whereas witnessed complex nocturnal behaviour and a medication-linked onset warrants assessment of a sleep-related mechanism NICE CKS,NICE CKS Unknown 2026. The supplied sleep-behaviour evidence concerns adult nocturnal eating and abnormal movements, not facial scratching in children, so it does not establish a parasomnia diagnosis in this child Unknown 2026.