Scabies

Scabies is an itchy skin condition that is often accompanied by a rash and scratching lesions. Typical for the diagnosis are the tunnels in the stratum corneum of the skin, including between the fingers and in other skin folds.

There are two forms of scabies:

• Scabies crustosa: this form is highly contagious; infection occurs through direct skin contact, contaminated objects, or through the air.

• 'Ordinary' scabies: this form is less contagious; infection only occurs after intensive skin contact.

Both forms of scabies are caused by the same mite. Scabies crustosa occurs in patients with a (severely) compromised immune system. When someone with normal immunity becomes infected with scabies crustosa, they develop normal scabies.

Prolonged (15 minutes or longer) or frequent direct skin-to-skin contact, sharing beds, clothing, etc. In the case of scabies crustosa, infection can occur via skin flakes present in the air.

From the moment mites are present on the skin (1-2 weeks after infection) until 12 hours after the start of the first treatment, including the implementation of the associated hygienemeasures. A second treatment is necessary for effective treatment.

2-6 weeks. Shorter in case of reinfection (1-4 days). Longer in immunocompromised individuals (up to 10 weeks).

No vaccine is available.

With ordinary scabies, there is a risk of infection after prolonged (more than 15 minutes) or frequent skin-to-skin contact. Short-term contact is probably insufficient for the scabies mite to spread.

With scabies crustosa, the risk of infection is much greater and, in addition to brief skincontact, can also occur via skin flakes in the air. Even a (short) stay in the same room can lead to infection in this way.

• Living in places where many people live in close proximity, such as student housing.
• Having contact with infected persons or infectious materials at work.

• People with an immune disorder or reduced immunity due to medication.
• People with chronic conditions such as autoimmune diseases, diabetes mellitus, liver and kidney disorders, or malnutrition.
• People with sensory dysfunction of the skin (reduced sensation) or pre-existing serious skin disorders.

In healthcare institutions, ambulance services, and shelters for the homeless and asylum seekers. For a complete overview, see the SRI guideline on scabies.

See SRI guideline on isolation. Depending on the isolation policy of your umc; gloves, barrier gowns.

‘Ordinary’ scabies: when a patient or employee is found to be infected with scabies, it is important to identify whether there have been any high-risk contacts. These are people who have had prolonged (longer than 15 minutes) or frequent intensive skin-to- skin contact with an index case during the contagious period. This includes, for example, employees who provide physical care. These high-risk contacts must be treated. It is important to treat them simultaneously as much as possible and to strictly follow the associated washing instructions.

Scabies crustosa: due to its high contagiousness, including via skin flakes in the air, it is very important to immediately identify and treat all contacts. It is recommended to form an Outbreak Management Team for this purpose and, if employees are involved, to add a company doctor to the OMT.

• Scabies | LCI guideline RIVM