Erythema Multiforme
Description Diagnostic criteria General and supportive measures Medicine treatment Referral ICD-10 code: L51.9 DESCRIPTION An acute, self-limiting and commonly recurrent inflammatory eruption of the skin 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
General and supportive measures
ICD-10 code: L51.9
DESCRIPTION
An acute, self-limiting and commonly recurrent inflammatory eruption of the skin 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 mainly caused by:
- medicines, e.g. sulphonamides, phenytoin, phenobarbitone,
- exposure to toxic substances, and
- infections, e.g. herpes simplex and mycoplasma.
Complications include:
- conjunctivitis,
- uveitis,
- corneal scarring,
- fluid loss,
- infections,
- anaemia, and
- oesophageal strictures.
DIAGNOSTIC CRITERIA
Iris or target lesions consisting of a dark centre, an inner pale ring and an erythematous outer border. In erythema multiforme these lesions are pathognomonic.
Erythematous macules evolve into papules, vesicles, bullae, urticarial plaques or patches of confluent erythema. The centre of the lesion may be vesicular, purpuric or necrotic.
Erythema multiforme minor
Prodromal symptoms are generally absent. Symmetric crops of skin lesions of diverse morphology, primarily on the extensor surfaces of the arms and legs and often including soles and palms with relative sparing of the mucous membranes and the trunk.
Erythema multiforme major (often equated with Stevens-Johnson syndrome)
A serious, systemic condition involving the skin and at least two mucous membranes.
Eruption may be preceded by non-specific prodromal symptoms including:
- malaise,
- fever,
- rigors, or
- upper respiratory tract infection.
Cutaneous lesions tend to rupture, leaving the skin denuded leading to fluid loss, with high risk of infection. Anaemia is common. The oral mucosa is frequently involved.
GENERAL AND SUPPORTIVE MEASURES
- May require care in a high or intensive care unit.
- Examine daily for systemic involvement, infection and ocular lesions. If infection is suspected, send blood and skin lesion specimens for culture and sensitivity before initiating antibiotic therapy.
- Do not puncture bullae or vesicles.
- Cool compresses and wet dressings.
- Encourage oral fluids to prevent adhesions.
- Regular supervised oral, genital and eye care to prevent adhesions and scarring.
- Maintain fluid balance. Beware of shock.
- Nasogastric feeds if unable to eat; IV alimentation if enteral feeds are not possible.
- Stop all potentially causative medicine
MEDICINE TREATMENT
For pain
These patients require effective pain control.
Change of dressing protocol: See Pain Control.
Dressings
Skin hygiene, daily cleansing and bland, non-adherent dressings as needed.
| Do not use silver sulfadiazine if Stevens-Johnson syndrome is thought to be due to cotrimoxazole or other sulphonamide. |
Antibiotic therapy
For secondary infections:
Use IV antibiotics if the oral route cannot be used.
- Cloxacillin, IV, 50 mg/kg/dose 6 hourly.
OR
- Cephalexin, oral, 25 mg/kg/dose 6 hourly.
Where weight is unknown:
◦ Child < 2 years: 125 mg.
◦ Child 2–10 years: 250 mg.
◦ > 10 years: 500 mg.
OR
- Flucloxacillin, oral, 25 mg/kg/dose 6 hourly
Penicillin allergy:
- Clindamycin, oral, 6 mg/kg/dose, 6 hourly.
Reconsider choice of antibiotic when the results of cultures become available or the child does not improve.
If Herpes Simplex Virus (HSV) is suspected to be the cause:
- Aciclovir, oral, 250 mg/m2/dose 8 hourly for 7 days.
For oral lesions
- Chlorhexidine 0.2%, 15 mL as a mouthwash.
- Use as needed.
- Do not swallow.
Note: The use of systemic corticosteroids is not recommended.
REFERRAL
- Erythema multiforme not responding to adequate therapy.
- Erythema multiforme with ocular involvement.
Standard Treatment Guidelines And Essential Medicines List For South Africa, Hospital Level, Paediatrics, 2023 Edition
Chapter 5: Dermatology, 5.2 Erythema And Desquamation, 5.2.1 Erythema Multiforme