Rashes and what they mean

Rashes generate more parental alarm than almost any other symptom, and the great majority are viral, self-limiting and irrelevant.

The one that matters most

A non-blanching rash — one that does not fade when pressed with a glass — can indicate meningococcal disease or another cause of bleeding into the skin, and requires emergency assessment.

Critically: the rash is a late sign and may be absent entirely.

Which means a child who is very unwell, drowsy, floppy, with cold hands and feet, rapid breathing, severe leg pain, neck stiffness, photophobia or a high-pitched cry needs emergency help regardless of whether there is a rash.

Do not wait for a rash to appear.

Small non-blanching spots can also occur after forceful coughing or vomiting, confined to the face and upper chest, in an otherwise well child — but the safe approach is always to have it assessed urgently.

Common viral rashes

The bulk of what parents see.

Hand, foot and mouth disease: spots and blisters on the hands, feet and in the mouth, with fever, mild and self-limiting.

Mouth ulcers may reduce drinking, which is the main practical concern.

Roseola: several days of high fever, followed by the fever resolving and a pink rash appearing — the rash appearing as the child improves is the characteristic feature.

Slapped cheek: bright red cheeks followed by a lacy rash on the body.

Generally mild, with specific concerns in pregnancy and in children with certain blood conditions.

Chickenpox: crops of itchy spots becoming blisters then crusts, appearing over several days.

Generally mild and occasionally complicated, with vaccination available in some countries.

Non-specific viral rashes, which are extremely common and unclassifiable.

Rashes that are not infections

Also common.

Eczema: dry, itchy, red patches, typically on the face in infants and in the skin creases in older children, managed with generous emollients and appropriate topical steroids.

Heat rash: tiny red spots in hot weather or when overdressed, resolving with cooling.

Urticaria: raised itchy weals that move around and come and go, frequently triggered by viral illness, sometimes by allergy, and responsive to antihistamines.

Widespread urticaria with any breathing difficulty or facial swelling is a different matter and is an emergency.

Contact dermatitis from products, saliva or friction.

Nappy rash, discussed elsewhere on this site.

And the various benign newborn rashes: milia, erythema toxicum, neonatal acne and cradle cap.

Rashes needing prompt but not emergency review

A middle category.

Impetigo: golden crusted sores, contagious, requiring treatment.

Scabies: intensely itchy, worse at night, with burrows and frequently affecting the whole household.

Ringworm: a scaly ring with a clearer centre, fungal and treatable.

Cellulitis: spreading redness, warmth and tenderness, needing antibiotics.

Any rash with significant blistering or peeling.

Any rash affecting the eyes or spreading rapidly.

And any rash in a baby under three months with a fever.

Measles

Worth a separate note given resurgence in several countries.

Fever, cough, runny nose and red eyes for several days, then a rash starting on the face and spreading downward, and small white spots inside the mouth.

It is highly contagious and causes serious complications including pneumonia, encephalitis and death, and it suppresses immunity to other infections for a prolonged period afterwards.

Suspected measles should be discussed by phone before attending a clinic, because of the infection risk to others.

Vaccination is highly effective and is the reason it was rare for a period.

What to do at home

For an ordinary viral rash in a well child.

Fluids and comfort.

Paracetamol or ibuprofen for fever or discomfort — with the caveat that ibuprofen is generally avoided in chickenpox because of a possible association with skin complications.

Cool loose clothing and a cool bath for itching.

Emollients.

Antihistamines for itching in older children, on advice.

Keeping nails short to reduce damage from scratching.

And monitoring how the child is rather than how the rash looks, which is the more informative measure.

The general rule

How the child is matters more than what the rash is.

A cheerful child with a dramatic rash is usually fine.

An unwell child with a subtle rash, or with no rash at all, is the one to worry about.

And photographing a rash is useful, since rashes change and clinicians frequently see them at a different stage.

General information only, not medical advice. Seek emergency care for a rash that does not fade under pressure, or for any child who is very unwell, drowsy or has difficulty breathing.