Scabies is one of those conditions that parents are initially reluctant to consider because it carries an unfair association with poor hygiene. In reality, scabies has nothing to do with cleanliness. The mite Sarcoptes scabiei cannot tell the difference between a clean and a dirty person, and it spreads through the kind of prolonged skin contact that is entirely ordinary in family life – sharing a bed, being held, playing together. Nurseries, schools, and households are all common transmission settings.
What makes scabies particularly persistent is that it's easy to treat incompletely and then struggle to understand why it keeps coming back. The rules for treatment are specific, and every one of them exists for a good reason.
Healthbooq (healthbooq.com/apps/healthbooq-kids) covers common childhood skin conditions.
What Scabies Is
The female scabies mite burrows into the outer layer of skin (stratum corneum) and lays eggs. The burrows are tiny, S-shaped or thread-like tracks, typically 5-15mm long. Over several weeks, the immune system mounts a reaction to the mites, their eggs, and their faeces, causing the characteristic intensely itchy rash. This immune sensitisation is why the itch is so much worse at night (warmth increases mite activity and sensitisation response), and why first-time scabies takes 4-8 weeks to produce symptoms – the immune reaction needs time to develop.
Someone who has had scabies before can develop symptoms within 1-3 days of reinfection, because their immune system is already primed.
What It Looks Like
The rash consists of intensely itchy spots, blisters, and burrows, typically in specific locations: finger webs, wrists, elbows, ankles, nipples, and genitalia in older children and adults. In children under 2 years, the distribution is different: the palms, soles, face, neck, and scalp can all be affected – these areas are spared in adults.
Scratching damages the skin, and secondary bacterial infection (typically Staphylococcus aureus or Streptococcus) is common in children with scabies. Infected scabies lesions become crusted, weeping, or pus-filled.
Crusted (Norwegian) scabies is a severe form occurring in people with weakened immune systems, in whom millions of mites are present. It is highly infectious even via brief contact. It is rare in immunocompetent children.
Treatment
Permethrin 5% cream is first-line treatment for all household members and close contacts aged 2 months and above. It is applied to cool, dry skin over the entire body from neck to toes in adults and older children, and from hairline to toes (including neck, face, and scalp) in children under 2 years. It should be left on for 8-12 hours before washing off. The process is repeated one week later – two full applications, one week apart.
The key rules that are frequently missed:Under fingernails, especially if the child has scratched: apply cream under the nails with an old toothbrush or similar.
The entire body must be covered, including skin folds, between toes, and the genital area.
Cream applied to hands should be reapplied after handwashing.
All household members must be treated at the same time on the same day, regardless of symptoms. An untreated household member will reinfest treated members. This is the single most common cause of treatment failure.
Malathion 0.5% aqueous lotion is used if permethrin fails or cannot be used.
Oral ivermectin (off-licence in the UK) is used for crusted scabies, for cases where topical treatment has failed, and in large institutional outbreaks. It is not first-line in uncomplicated cases.
Treating the Environment
Scabies mites cannot survive off the human body for more than 2-3 days. Bedding, clothing, and towels used in the 3 days before treatment should be machine washed at 60°C or above. Items that cannot be washed can be bagged and left sealed for 3 days. There is no need to fumigate or treat furniture.
Managing the Itch After Treatment
Itching after successful treatment is expected and common. The immune response to dead mites, eggs, and faeces continues for 4-6 weeks after treatment. This is not treatment failure and does not mean the mites are still present. Crotamiton cream or a mild antihistamine (such as chlorphenamine) can help manage the itch during this period. If a new rash appears or itching returns intensely after the 6-week post-treatment period, reassessment is needed.
Schools and Childcare
A child does not need to be excluded from school or nursery once treatment has started. PHE (Public Health England, now UKHSA) guidance states that treated children can return to school the day after treatment. If several children in the same class have scabies, the school's linked health protection team may advise on a class-level response.
Key Takeaways
Scabies is a highly contagious skin infestation caused by the mite Sarcoptes scabiei, which burrows into the skin and causes intense itching, particularly at night. It affects all ages and socioeconomic groups and spreads through prolonged skin-to-skin contact, most commonly within households. Permethrin 5% cream is the first-line treatment in the UK for adults and children over 2 months; malathion is used if permethrin fails. Treatment must be applied to the entire body from neck to toes (neck, scalp, and face in children under 2) and all household contacts must be treated simultaneously, even if symptom-free, or reinfestation will occur. Itching can persist for 4-6 weeks after successful treatment due to the immune reaction.
