Laterothoracic exanthem is also known as Asymmetric Periflexural Exanthem of Childhood (APEC). It is an uncommon rash affecting young children, which is suspected to be due to a viral infection.
Laterothoracic exanthem mainly occurs in winter and spring and affects twice as many girls as boys. The average age is two, most cases being between one and five years old.
The rash is often mistaken for eczema (dermatitis) or a fungal infection (ringworm). It usually starts in the armpit or groin and gradually extends outwards, remaining predominantly on one side of the body. It may spread to the face, genitalia, hands or feet.
The rash starts as tiny raised pink spots, which may be surrounded by a pale halo, then slowly becomes flat and scaly. The middle of older patches fades to a dusky grey. Occasionally the patches are net-like or in rings. Little blisters or blood spots may occur. The rash is usually quite itchy.
Sometimes other features of viral infection occur at the onset of the rash, such as a fever, sore throat, cold, vomiting and/or diarrhoea. The lymph glands in the armpits and groins may be enlarged.
The rash lasts for several weeks, but always resolves spontaneously within three months.
The rash will clear without treatment. The itching can be relieved with: