Page 14 of 20

DR12.5 | Cutaneous Adverse Drug Reaction Primary Care — SDL Guide (Part 3)

Tier-by-Tier Management Summary

A tiered drug reaction management ladder shows stopping the culprit drug first, escalating from mild rash to SJS/TEN, with pharmacovigilance duties and referral boundaries. — **Panel A:** Drug reaction management ladder: mild maculopapular rash or urticaria, airway-threatening angioedema, fixed drug eruption, DRESS, SJS/TEN, with stop culprit drug first at every tier.. **Panel B:** Universal duties: document culprit drug and reaction, report adverse drug reaction, counsel permanent avoidance.. **Panel C:** Primary-care boundary: supportive and symptomatic treatment plus urgent referral; specialist-only decisions for systemic steroids, immunomodulators, and definitive DRESS or TEN care..

Bringing the management together as a single ladder makes the primary-care response easy to apply under pressure, with the constant rule that drug cessation is the first step at every tier. For a mild maculopapular rash or urticaria: stop the drug, give antihistamines and a topical steroid, provide safety-net advice, and treat airway-threatening angioedema with adrenaline and transfer. For a fixed drug eruption: stop the drug, topical steroid for the lesion, and counsel lifelong avoidance. For DRESS: stop the drug and its whole class, take baseline blood count and liver/renal function, treat the skin symptomatically, refer urgently, and leave systemic steroids to the specialist. For SJS/TEN: stop the drug, give burns-model care (fluids, wound and mucosal care, analgesia, warmth), arrange urgent ophthalmology and emergency transfer, document BSA/SCORTEN, and do not start systemic immunosuppression.

Across every tier, two duties never change. Pharmacovigilance: document the reaction and the culprit drug and report it, and ensure the patient knows what to avoid permanently. And knowing the limits of primary care: the generalist initiates supportive and symptomatic treatment and refers, but does not start the disputed or specialist-only therapies (systemic steroids in TEN, immunomodulators, definitive DRESS treatment) that belong to the referral centre. This combination — confident graded primary care plus clear boundaries — is exactly what competency DR12.5 requires.

A color-coded primary-care management table shows escalation from mild drug rashes to DRESS, SJS, and TEN with drug cessation, treatment, referral urgency, and actions to avoid. — **Panel A:** Risk escalation pathway from mild exanthem/urticaria to FDE and severe cutaneous adverse reactions, with labels for airway assessment, red flags, drug cessation, documentation, and pharmacovigilance reporting.. **Panel B:** Tiered management table for maculopapular exanthem, urticaria/angioedema, fixed drug eruption, DRESS, SJS, and TEN across immediate step, drug cessation, skin care, GP-level systemic treatment, referral urgency, and what not to do..

Mild rash / urticaria: stop drug; antihistamine + topical steroid; adrenaline + transfer for airway angioedema.
Fixed drug eruption: stop drug; topical steroid; counsel lifelong avoidance.
DRESS: stop drug + class; baseline FBC/LFT/RFT; symptomatic skin care; refer urgently; systemic steroids = specialist.
SJS/TEN: stop drug; burns-model care; urgent ophthalmology + emergency transfer; document BSA/SCORTEN; no systemic immunosuppression in primary care.
Every tier: document + report (pharmacovigilance); know the limits of primary care.

SELF-CHECK

A patient had a fixed drug eruption to co-trimoxazole. He now needs an antibiotic again and asks if he can take co-trimoxazole at a lower dose to 'test' whether it still affects him. What is the correct advice?

A. Yes — a low-dose re-challenge safely confirms the diagnosis

B. No — re-exposure reliably reproduces the reaction; he must permanently avoid the culprit drug and be given an alternative

C. Yes — provided an antihistamine is taken alongside

D. It does not matter, as fixed drug eruption never recurs

Reveal Answer

Answer: B. No — re-exposure reliably reproduces the reaction; he must permanently avoid the culprit drug and be given an alternative

Re-exposure to the culprit drug reliably reproduces a fixed drug eruption at the same site (and may worsen or generalise it). Deliberate re-challenge is unsafe; the patient must be counselled to avoid that drug permanently and given a documented alternative — a core pharmacovigilance and primary-care responsibility.

Applying the Primary Care Response

A four-panel medical education diagram shows recognition, immediate stabilisation, severity-tiered care, and referral documentation for primary care management of severe drug reactions such as SJS/TEN. — **Panel A:** Clinical recognition of severe drug reaction: painful detaching skin, mucosal erosions, eye involvement, suspected sulfonamide culprit, SJS/TEN red flags.. **Panel B:** Immediate primary care actions: stop culprit drug, secure IV access, begin fluids, give analgesia, provide non-adherent wound care and warmth, estimate body surface area involved.. **Panel C:** Severity-tiered response: mild reaction with reassurance and symptomatic treatment, DRESS with baseline organ assessment and urgent referral, SJS/TEN with burns-model stabilisation and emergency transfer.. **Panel D:** Referral and limits of primary care: alert ophthalmology, document reaction, report adverse drug reaction, arrange emergency transfer, avoid starting systemic steroid in primary care..

The final skill is to deploy this graded response fluently when a real patient with a drug reaction arrives. Return to the man with early toxic epidermal necrolysis from the opening: the correct sequence is to recognise the severe features (mucosal erosions, painful detaching skin), stop the sulfonamide immediately, secure intravenous access and begin fluids, provide gentle non-adherent wound care and warmth, give analgesia, alert ophthalmology for his eye involvement, estimate the body surface area involved, document the reaction, and arrange emergency transfer to a burns unit — all the while not reaching for a systemic steroid, which is not his to start. That ordered response, executed in a basic health centre, is what gives the patient the best chance.

Three principles should now be automatic. First, stop the culprit drug in every reaction, whatever its severity — it is always the most important step. Second, match the intensity of care to the tier: reassurance and symptomatic treatment for the mild, baseline organ assessment and urgent referral for DRESS, and burns-model stabilisation with emergency transfer for SJS/TEN. Third, know and respect the limits of primary care — initiate supportive treatment and refer, but leave specialist and disputed therapies to the referral centre, and always document and report the reaction so the patient is protected in future.

Apply the sequence: recognise severity → stop the drug → tier-appropriate care → document → refer.
For SJS/TEN: stop drug, fluids, wound/mucosal care, analgesia, ophthalmology, BSA/SCORTEN, emergency transfer — no systemic steroid in primary care.
Three principles: always stop the culprit drug; match care to tier; respect the limits of primary care and document/report.

CLINICAL PEARL

When a severe drug reaction lands in front of you, anchor on two things you can always do regardless of resources: stop the culprit drug, and — for SJS/TEN — treat the patient like a burns case (fluids, gentle wound care, warmth, analgesia) while you arrange transfer. Resist the urge to 'do more' by starting systemic steroids in TEN: their benefit is unproven and they may cause harm, so that decision belongs to the specialist. Doing the simple, correct things well, and not the disputed things, is what saves these patients.