Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.
2 min synopsisUK scopeSources checked 27 Aug 2026Clinical review pending
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Anaphylaxis, sepsis or severe cutaneous reaction
Itch with airway swelling, breathing difficulty or circulatory collapse may be anaphylaxis. Sweating with fever, rigors, hypotension or confusion may be sepsis. Skin pain, mucosal ulceration, blistering or widespread detachment after a medicine suggests a severe cutaneous adverse reaction.
Action: Use ABCDE assessment and call emergency help. Give intramuscular adrenaline for suspected anaphylaxis under the current Resuscitation Council UK pathway, treat sepsis promptly, stop a suspected culprit medicine in severe skin reaction and obtain urgent allergy, dermatology, burns or acute medical support while continuing comfort and documenting escalation wishes.
Synopsis
Identify causes of itch and sweating, recognise emergencies, protect skin and select mechanism-specific treatment without avoidable sedation or anticholinergic harm.
First-line assessment maps timing, triggers, rash before scratching, systemic clues, medicines and effects on skin and sleep.
Treat airway swelling, wheeze, shock or rapidly spreading urticaria as possible anaphylaxis; fever with rigors, hypotension or confusion requires urgent infection assessment.
First-line itch care uses a cool environment, soap substitute, regular fragrance-free emollient, short nails, loose cotton clothing and treatment of the primary skin disorder.
Key red flags
Tongue or throat swelling, stridor, wheeze, hypoxia, hypotension or collapse with itch is anaphylaxis until proven otherwise.
Anaphylaxis or severe drug reaction
Airway swelling, wheeze, shock, mucosal erosion, blistering, skin pain or systemic illness requires emergency treatment and immediate culprit-drug review.
Investigation priorities
01
First-line skin and systemic historyFirst stepFirst line
Determine rash timing, distribution, water or heat triggers, contacts, jaundice, renal disease, fever, weight loss, medicines and effect on sleep.
02
Targeted first-line blood panelFirst line
Use full blood count, ferritin, renal, liver, calcium, glucose, thyroid and inflammatory testing when systemic disease is plausible and actionable.
Management branches
Immediate safetySeparate allergy, infection and severe drug reaction
Itch or sweating is acute with airway, breathing, circulatory, fever, mucosal or blistering features.
Use ABCDE assessment, remove likely exposure, check observations and glucose and identify anaphylaxis, sepsis, cholangitis or severe cutaneous reaction.
Give emergency treatment under the relevant pathway, stop suspect medicines when safe and obtain acute specialist help without delaying symptom relief.
Key medicines
Non-sedating antihistamine for urticariaFor histamine-mediated urticaria, cetirizine 10 mg orally once daily is a common adult regimen; adjust for renal function and follow urticaria guidance if specialist up-dosing is considered.
Cholestyramine for cholestatic pruritusBegin with 4 g orally once or twice daily and titrate under hepatology or palliative guidance; take other oral medicines at least 1 hour before or 4 to 6 hours after each dose.
National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.