Scabies: Why the Itching Is Worst at Night and What a Visit Can Do

What it involves

MedlinePlus describes scabies as an easily spread skin disease caused by a very small mite. The mites burrow into the skin and lay eggs, and the itchy rash is an allergic response to the mite. It affects people of all groups and ages around the world.

Who this is for

• Adults with severe itching, especially at night, that has not settled
• People with a rash between the fingers, on the wrists, in the armpits or at the waist
• Household members or partners of someone diagnosed with scabies
• Patients who work or live in nursing homes, child care or other close-contact settings

What to expect

• Questions about when the itching began, where it is worst and whether anyone close to you is itching too
• A look at the skin for burrows, rash and scratch sores
• A discussion of treatment, which is a prescription cream or lotion, and who else in the household should be treated
• Instructions for washing clothing and bedding, and what to expect while the itching fades

How scabies spreads

MedlinePlus says scabies spreads by skin-to-skin contact with another person who has it, and that whole families are often affected. Outbreaks are more common in nursing homes, college dorms and child care centers. The CDC summary on its health topic page adds that sharing clothes, towels and bedding can sometimes spread it. Pets and animals usually do not spread human scabies, and spread through swimming pools is very unlikely, so there is rarely a reason to blame the family dog.

What it looks and feels like

The main symptom is severe itching, most often at night. MedlinePlus lists a rash often found between the fingers and toes, on the undersides of the wrists, in the armpits, on the breasts and on the buttocks, sores from scratching, and thin lines called burrow marks that look like pencil marks. Scabies does not usually affect the face except in babies and in people with crusted scabies. Many other conditions itch too, so the itchy skin guide covers the wider list of causes.

How it is diagnosed

MedlinePlus says a provider examines the skin for signs of scabies, and that tests may include scraping a burrow to look for mites, eggs or droppings under a microscope, or sometimes a skin biopsy. Often the story and the look of the rash tell most of it. Be ready to say who else in the house is itching, when the itching started and whether you recently stayed in a shared setting, because that history is as useful as the skin exam.

Treatment and household steps

The encyclopedia explains that creams or lotions prescribed by a provider are needed to treat scabies, that permethrin 5 percent is the medicine most often used, and that the treatment is typically repeated in one week. For hard-to-treat cases a provider may add a pill. Everyone in the household and sexual partners should be treated even without symptoms. Before treatment, wash clothing, towels and bedding in hot water and dry them at 140 degrees Fahrenheit or higher, or keep items away from the body for at least 72 hours.

What to expect after treatment

MedlinePlus says itching may continue for two weeks or more after treatment ends and will most likely disappear if you follow the plan. Most cases are cured without long-term problems. Intense scratching can cause a secondary skin infection such as impetigo, so a rash that becomes red, warm, swollen or crusted with fluid should be seen again, as the cellulitis guide explains. Calamine lotion, a cool bath or an oral antihistamine, if your provider recommends one, can ease the itching meanwhile.

Crusted scabies is a different problem

MedlinePlus describes crusted, or Norwegian, scabies as a severe infestation with very large numbers of mites that mostly affects people whose immune systems are weakened. A severe case with a lot of scaling or crusting may be a sign of a weakened immune system. Thick crusts on the skin are not a home-remedy situation and should be seen without delay. Other rashes with a different cause, such as eczema, can look similar at first.

Sources

• MedlinePlus: Scabies (medical encyclopedia)
• MedlinePlus: Scabies (health topic, CDC)