Comment: We might think of scabies as a disease from the past, but it remains a surprisingly common problem in New Zealand and the Western Pacific. Our research has found that in some South Auckland preschools about half of children have the condition. Far from causing just an itchy rash, the condition is linked to skin infections, kidney disease, rheumatic fever and rheumatic heart disease.
Along with colleagues at the University of Auckland and other health leaders, I have argued in the New Zealand Doctor ($) that we need to stop viewing scabies as a nuisance skin condition and instead as a public health priority.
Scabies is caused by a tiny mite, about half the size of a pin head, that burrows into the skin and lays eggs. The body’s reaction causes intense itching and a rash that often gets worse at night. It spreads through close skin-to-skin contact, making it common among family members living in the same house. Doctors often refer to affected households as having an “itch in the family”.
Many think of scabies as an irritating but harmless condition; however this isn’t the case. Evidence our team has collected in New Zealand and in Tonga indicates that scabies leads to much more serious illnesses. Scabies interferes with natural immune processes leading to colonisation of the skin with harmful bacteria. These infections can then lead to impetigo, cellulitis, abscess and kidney disease. We have found a very strong correlation between children with scabies and children with rheumatic heart disease in several studies in NZ and Tonga, although whether scabies is a cause of the more serious heart condition is still contested. Many of these diseases linked to scabies entail the need for costly surgery or other interventions and premature death.
Why does it persist?
One reason scabies remains common is that it is often missed or misdiagnosed. The symptoms can look like other skin conditions, making diagnosis difficult. In an Auckland study, we found that many children with scabies had been told they had eczema, allergies or insect bites. As a result, people may go untreated for weeks or even months while continuing to spread the mite to others. The disease is widespread across many Pacific island nations, and New Zealand’s close links with the Pacific mean cases continue to occur here.
The good news is that scabies is one of the most treatable conditions in medicine, requiring only two doses of a lotion or tablet. The challenge is that treating one person is not enough. If household members aren’t treated at the same time, even those with no skin symptoms, mites can quickly spread back to those who have already completed treatment. People can conclude that the treatment is futile.
The treatment problem
The standard treatment is permethrin cream, which kills the mites when applied all over the body. Permethrin cream can be bought over the counter, for about $10 a bottle: treating a household or extended family can be costly.
Another medicine, ivermectin, can be taken as a tablet and is often easier to use because it doesn’t require intensive and complicated ‘head-to-toe’ application that permethrin cream does. But it needs a GP prescription and special authority for funding.
We argue that access to ivermectin should be made easier to access in New Zealand because treatment is often more practical and effective than topical creams, particularly in large households. Currently, administrative hurdles get in the way of doctors prescribing the drug. Follow-up care should be funded so families can make sure treatment has worked. Treating scabies successfully is not just about helping one patient. It’s about breaking the chain of transmission.
A public health issue
The strongest argument for change is that this is an equity issue. Scabies hits some communities much harder than others; rates are highest in communities living in overcrowded homes, tight budgets and those facing barriers to healthcare. These same communities already carry a heavy burden of health problems, including skin infection, rheumatic fever and rheumatic heart disease.
Controlling scabies could potentially have benefits far beyond reducing itching and skin rashes. It may help prevent some of New Zealand’s most serious childhood illnesses.
What should New Zealand do?
The answer lies in community-wide action rather than relying on individuals to manage the problem on their own. Doctors are often taught to look for the classic signs of scabies, such as visible burrows in the skin, but many people with scabies don’t have these. Cases are missed, allowing the mite to move onto its next host. Instead the more frequent signs are clusters of small raised red itchy spots (papules) on the forearms, hands, lower legs and feet, along with symptoms of itch in the affected patient or family.
Schools, early childhood centres, and rest homes could play a larger role in identifying outbreaks. Screening in these areas to identify and treat cases could have a large benefit to the community and help health authorities track progress. We also need to consider helping Pacific Island nations, such as Tonga, Samoa and the Cook Islands identify and treat cases and conduct population-wide treatment if necessary.
Public education is also important. Health promotion campaigns could help reduce stigma and encourage families to seek treatment for itch early.
Scabies remains one of New Zealand’s most overlooked health problems. It causes discomfort, disrupts sleep, affects school attendance and can contribute to more serious diseases. The question may not be why New Zealand still has scabies. The more important question is why a condition with effective treatments continues to thrive among the communities already living with the greatest health needs. Tackling scabies offers a rare opportunity to reduce suffering, improve health equity and prevent more serious illness.
