L42
DESCRIPTION
A common disease of unknown cause, probably due to a viral infection as it occurs in minor epidemics. Most common in young adults but any age may be affected. The rash involves the trunk, neck and mainly proximal parts of the limbs.
Presents as pink papules and macules. The macules are oval, and have a thin collar of scale towards, but not at the periphery of the lesions. The eruption is usually preceded by a few days by one larger, oval, slightly scaly area (“herald patch”), commonly found in the scapular area or abdomen. The macules on the thorax characteristically lie parallel to the long axis of the ribs (“Christmas tree” distribution).
The itch is usually mild and there are few or no constitutional symptoms. It is self-limiting within about 6–8 weeks.
GENERAL MEASURES
Explain about the benign but prolonged nature of the condition.
MEDICINE TREATMENT
Children
- Chlorphenamine, oral, 0.1 mg/kg/dose at night. Seepaediatric dosing tool.
Adults
- Chlorphenamine, oral, 4 mg at night.
Note: Chlorphenamine is sedating.
If itch not controlled or more severe daytime itch, switch to:
Children: 2–6 years of age
- Cetirizine, oral, 5 mg once daily. See paediatric dosing tool.
Children > 6 years of age and adults
- Cetirizine, oral, 10 mg once daily.
CAUTION
Do not give an antihistamine to children < 2 years of age.
- Aqueous cream, applied 3 times daily.