L51.0-2/L51.8-9
DESCRIPTION
Erythema multiforme
An acute, self-limiting, and commonly recurrent inflammatory skin eruption with variable involvement of the mucous membranes and without systemic symptoms.
Symmetrically distributed crops of target lesions (dark centre, an inner, pale ring surrounded by an outer red ring) often involving palms and soles are characteristic. This condition is usually due to an infection, commonly herpes simplex or mycoplasma.
Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN)
Life-threatening acute hypersensitivity reactions with systemic upset, epidermal necrosis, and mucous membrane involvement. TEN and SJS are different ends of the same spectrum: in TEN epidermal necrosis involves >30% of body surface area, while in SJS the involvement is <10%. Non-specific prodromal symptoms, often mistaken as an upper respiratory tract infection, may occur before skin lesions are apparent.
Cutaneous lesions may start as a dusky red macular rash, progressing to confluence with epidermal necrosis and large flaccid blisters which rupture, leaving large areas of denuded skin. Mucous membrane erosions are common and multi-organ involvement may be present.
This condition is usually due to medication, e.g. sulfonamides, non-nucleoside reverse transcriptase inhibitors (especially nevirapine), anti-epileptics (phenytoin, phenobarbitone, carbamazepine, lamotrigine), allopurinol, laxatives (phenolphthalein).
Complications include:
- Dehydration, electrolyte disturbances and shock,
- hypoalbuminaemia,
- hypo- and more commonly hyperthermia,
- high output cardiac failure,
- secondary infection and sepsis, and
- adhesions and scarring.
Stop all medicines, where safely possible, including complementary, alternative, and self medication.
GENERAL MEASURES
Principles of management
Immediate in hospital evaluation
The foundation of management is supportive, good nursing, and the prevention of dehydration and sepsis.
Management is similar to that of burns.
Stop/substitute all medicines.
Patients usually require care in a high or intensive care unit with dedicated nursing.
Attempt to identify causative agent as early withdrawal of agent improves prognosis.
Monitoring
Monitor vital organ function.
Examine daily for infection and swab infected lesions. Do blood cultures if fever persists or suspicion of infection.
Dressings
Skin hygiene; daily cleansing and bland, non-adherent dressings as needed.
Do not use silver sulfadiazine if SJS/TEN is thought to be due to cotrimoxazole or other sulfonamides.
Mucous membranes:
Regular supervised oral, genital and eye care to prevent adhesions and scarring.
Two-hourly mouth washes with bland mouth wash, e.g. glycothymol.
Examine daily for ocular lesions and treat 2-hourly with eye care and lubricants (see section 18.9: Dry eye) and break down adhesions.
Treat genitalia 6-hourly with Sitz baths and encourage movement of opposing eroded surfaces to prevent adhesions.
Fluids:
Oral rehydration is preferred but intravenous fluid therapy may be required to treat significant dehydration.
Encourage oral fluids to prevent pharyngeal adhesions.
Provide soft, lukewarm food. Restrict nasogastric feeds to those patients that are unable to eat, as they may lead to additional trauma with bleeding, secondary infection and adhesions.
Note: All patients should receive a notification bracelet/necklace on discharge.
MEDICINE TREATMENT
Corticosteroids
The practice of using systemic corticosteroids is not supported by evidence and is therefore not recommended.
Antibiotic therapy
Systemic antibiotics may be indicated, depending on results of appropriate cultures. They should not be administered routinely, nor be given prophylactically. Organisms identified on skin swabs are not a good indicator of systemic infection.
Analgesia
Appropriate and adequate analgesia for the pain associated with dressing changes, given at least half an hour before dressing change. (See Perioperative analgesics).
REFERRAL/CONSULTATION
Discuss with a specialist, if considering re-initiation of medicine treatment.
Where there is ocular involvement, consult a specialist immediately.