Scabies vs eczema: why an itchy rash needs the right label

The biggest practical difference is that scabies is contagious and eczema is not. If other people in your household are itching, or the itch has appeared over weeks and is worst at night, scabies is a real possibility. If the itch is on dry, scaly skin in the creases of the elbows and knees, is on and off with flare-ups and runs in your family with asthma or hay fever, it is more likely to be eczema.

The NHS says scabies is caused by mites that spread through close skin contact, that anyone can get it and that it has nothing to do with poor hygiene. It says atopic eczema is a common skin condition that causes itchy skin and cannot be cured, although treatment can help to manage the symptoms. Because the rashes can look alike, and because scabies can make eczema worse, a persistent itch that is not responding to treatment deserves a proper assessment.

Scabies is an infestation. The NHS says tiny mites lay eggs in the skin, leaving lines with a dot at one end, and that it can take up to 8 weeks for the rash to appear after infection. The rash usually spreads across the whole body apart from the head and neck, although older people and young children may develop a rash on the head, neck, palms and soles of the feet. People with weakened immune systems can get a rare and very contagious type called crusted scabies, with a crusted, flaky rash often on the elbows, knees, hands and feet.

Atopic eczema, or atopic dermatitis, is most common in young children but affects people of all ages. The NHS says the skin can be itchy, dry, cracked, crusty, scaly or thickened, red, white, purple or grey or lighter or darker than the skin around it depending on your skin tone, and may blister or bleed. There are usually flare-ups and quieter periods. You are more likely to have it if one or both parents have it or you or a close relative has asthma or hay fever.

The table is based on the NHS pages for each.

For scabies, the NHS highlights night-time itching, a rash that is common between the fingers and around the wrists, underarms, waist, groin and bottom, and a household or close contacts who are also itchy. People who live or work closely together in nurseries, university halls of residence or nursing homes are more at risk. You cannot get scabies from pets.

For eczema, the pointers are a personal or family history of eczema, asthma or hay fever, skin that is dry or scaly in the elbow and knee creases, a pattern of flare-ups, and triggers such as soap, washing detergent, pets, some fabrics, heat, stress and infections. The NHS scabies page adds that if you are not sure it is scabies, many other things can cause itchy skin and rashes, particularly in babies and children.

The NHS says scabies is treated with a cream or lotion that a pharmacist can recommend, applied over the whole body including the scalp and face (avoiding the area around the eyes), then repeated 7 days later. Everyone in the home needs treatment at the same time, and anyone with whom you have had sexual contact in the past 8 weeks should also be treated. Bedding and clothing should be washed at 60C or higher on the first day, and anything that cannot be washed sealed in a bag for at least 3 days. Children under 2 need to see a GP. Adults and children aged 5 or over can go back to work or school once treatment has started, but should avoid close contact for the first 24 hours.

For atopic eczema, the NHS says the main treatments are emollients applied as often as possible, at least twice a day, and washing with an emollient instead of soap, together with steroid creams, lotions or gels. It advises avoiding triggers, keeping nails short, keeping cool and not scratching. A pharmacist can help with mild eczema, and a GP can prescribe other treatments or refer to a dermatologist.

The NHS says to see a GP if you have scabies and think your skin may be infected or you have another skin condition such as eczema, if you have a crusted, flaky rash on elbows, knees, hands or feet, if you have used pharmacy treatment and your skin is still itching 2 to 4 weeks after treatment finished, or if your child is under 2 or someone else in the household has scabies. Scratching can cause skin infections such as impetigo.

For eczema, the NHS says to ask for an urgent GP appointment or call NHS 111 if it is blistered, crusty, leaking fluid or has pus-filled spots, is painful, swollen or feels warm, suddenly gets worse or bigger, or you have a high temperature or feel generally unwell. These can be signs of infection or a more serious condition called eczema herpeticum.