Derm emergencies
One question runs through this page: what should make you worried? Recognition training only, none of this substitutes for assessing a real patient with real supervision.
SJS / toxic epidermal necrolysis
A drug rash where the skin hurts, blisters, or involves mucosa, the epidermis is dying in sheets.
The clues
- Skin PAIN, not itch
- Dusky targetoid macules
- Nikolsky sign, epidermis shears with lateral pressure
- Haemorrhagic lip crusting, painful eyes
- Culprit drug started 1–3 weeks ago
First moves
- Stop every plausible culprit drug now
- Escalate to senior/burn-level care
- Urgent ophthalmology review
Full picture in the Atlas: Stevens–Johnson syndrome / toxic epidermal necrolysis
Necrotising fasciitis
Piotr Smuszkiewicz, Iwona Trojanowska and Hanna Tomczak · CC BY 2.0
A 'cellulitis' where the pain is out of proportion and the patient is sicker than the skin looks.
The clues
- Pain beyond visible findings, or anaesthesia of overlying skin
- Rapid hour-by-hour progression
- Dusky grey discoloration, bullae, crepitus
- Systemic toxicity: hypotension, confusion
First moves
- Immediate senior and surgical involvement, this is a surgical diagnosis
- Broad-spectrum antibiotics and resuscitation alongside, never instead
Fever with petechiae / purpura
Hlei A.I., Shkurba A.V. · Public domain
Non-blanching rash plus fever is meningococcal sepsis until proven otherwise.
The clues
- Petechiae spreading or coalescing into purpura
- Fever, rigors, headache, neck stiffness
- Ill-looking, hypotensive, or drowsy patient
- The glass test: the rash does not blanch
First moves
- Immediate senior escalation and sepsis pathway
- Do not wait for the rash to declare itself further
Eczema herpeticum
HSV sweeping across broken atopic skin, punched-out erosions where eczema used to be.
The clues
- Atopic patient acutely worse and febrile
- Monomorphic punched-out erosions and vesicles
- Pain replacing the usual itch
- Clustered near active dermatitis, spreading fast
First moves
- Systemic antivirals early
- Same-day ophthalmology if periocular
- Do not start or intensify topical steroids over it
Erythroderma
Redness of >90% of the body surface, the skin is failing as an organ, whatever the cause.
The clues
- Generalised redness and scaling
- Shivering, temperature instability
- Tachycardia, oedema, high-output strain
- Background psoriasis, eczema, drug, or lymphoma
First moves
- Admit: fluid balance, temperature, and nutrition support
- Hunt the cause while supporting the skin
Urticaria with anaphylaxis features
James Heilman, MD · CC BY-SA 4.0
Hives are benign, until the airway, breathing, or circulation join in.
The clues
- Lip, tongue, or throat swelling
- Wheeze, stridor, hoarseness
- Hypotension, presyncope
- Onset minutes after food, drug, or sting
First moves
- Treat as anaphylaxis: intramuscular epinephrine per protocol, call for help
- Antihistamines are for the hives, never for the airway
Zoster with eye risk (V1 / Hutchinson sign)
James Heilman, MD · CC BY-SA 4.0
Vesicles on the nasal tip mark nasociliary nerve involvement, the cornea shares that nerve.
The clues
- Rash in the V1 distribution: forehead, upper lid
- Vesicles on the tip or side of the nose
- Red eye, photophobia, blurred vision
First moves
- Same-day ophthalmology referral
- Systemic antivirals promptly
The changing pigmented lesion
Unknown author · Public domain
Evolution is melanoma's signature, a mole that changes has earned expert eyes.
The clues
- Change in size, shape, or colour over months
- The ugly duckling unlike its neighbours
- New pigmented band in a nail with fold spill-over (Hutchinson)
- Bleeding or itch in a mole (late)
First moves
- Refer for dermoscopy and excisional biopsy
- Never partially shave a suspected melanoma