Scabies is a contagious skin condition caused by the human itch mite Sarcoptes scabiei. The mites burrow into the upper layer of skin and lay eggs, causing an itchy rash to develop. Scabies is spread through direct, prolonged contact with someone who has scabies. Knowing the early signs and symptoms can help you identify and treat scabies quickly before the infestation spreads.
What are some common signs and symptoms of scabies?
Some of the most common signs and symptoms of scabies include:
- Intense itching, especially at night – The urge to itch is often described as intolerable, with the most common areas being between fingers, wrists, elbows, armpits, waist, genitals, breasts, and shoulders.
- Rash – Small red bumps, blisters, pimples, or burrows may appear where mites have entered the skin. The rash often develops 2-6 weeks after initial infestation.
- Sores – Scratching the rash can cause sores that may become infected by bacteria.
- Thin, wavy lines – Mites burrow into skin, forming thin gray or white lines visible on the skin surface.
- Crusting skin – Continuous scratching may cause the skin to crust over.
Symptoms are often worse at night because the mites are most active in the dark. Signs and symptoms may continue for several weeks after treatment as skin healing occurs. Even after successful eradication, itching can persist due to lingering skin inflammation.
Where does the rash usually appear?
The rash of scabies is often found:
- Between the fingers
- Around the wrists
- On the elbows
- Under the arms
- On the thighs
- Around the waist and navel
- On the breasts
- On the male genitals
- On the buttocks
- On the ankles
In infants and young children, the rash may appear on the head, face, neck, palms, and soles of the feet. The rash tends to be found in skin folds and warm areas of the body.
Who is at risk for scabies?
Anyone can get scabies, however certain groups are at higher risk:
- People in contact with someone who has scabies
- Nursing home residents
- Child care providers
- Health care providers
- Institutionalized populations such as prisons, nursing homes, and psychiatric facilities
- People with weakened immune systems
- Young children and infants
Scabies easily spreads under crowded conditions where close body and skin contact is common. All it takes is brief skin-to-skin contact with an infected person for mites to spread.
How soon do symptoms appear?
For a person who has never had scabies before, symptoms may take 4-6 weeks to begin. For someone who has had scabies previously, symptoms usually appear within 1-4 days after coming into contact with mites.
This initial infestation period represents the time it takes for the female mite to burrow into the skin and for the sensitization and allergic reaction to develop. Subsequent exposures to mites will result in a more rapid allergic reaction and quicker onset of itch.
Can scabies spread without symptoms?
Yes, it’s possible to spread scabies without having any signs or symptoms yet. An infested person can transmit scabies mites to others during the 2-6 week period before irritation and itching begins. Once symptoms develop, a person is considered contagious until mites and eggs are completely eradicated from the body and bedding.
How do you diagnose scabies?
To diagnose scabies, a doctor will:
- Ask about symptoms, when they started, and risk factors
- Examine the rash and burrows
- Look for signs of scratching and sores
- Use a magnifying lens to look for mites, eggs, or mite fecal matter
- Take a skin scraping to view under a microscope
- Consider ordering blood tests to look for infection
Diagnosis can be challenging because symptoms resemble other skin conditions like eczema or hives. However, scabies should be suspected if there is an intense itch and rash affecting multiple family members, sexual partners, or people in confined living spaces. A definitive diagnosis often requires finding mites, eggs, or fecal fragments.
What conditions are similar to scabies?
A number of other skin conditions can mimic the signs of scabies, including:
- Eczema
- Contact dermatitis
- Psoriasis
- Hives
- Insect bites
- Impetigo
- Chickenpox
- Shingles
What distinguishes scabies is the burrows seen from mites digging into skin. The intense itch, often worse at night, also differentiates it from many mimic conditions. A doctor can help discern scabies from look-alike rashes through a physical exam, microscopic tests, and response to treatment.
When should you seek medical care for scabies?
You should see a doctor right away if:
- You develop an itchy rash that gets worse at night and affects your entire household
- The itching and skin irritation is severe
- Sores or skin infections develop from excessive scratching
- You have a weakened immune system and suspect scabies
- Your infant or small child exhibits unusual irritability, rash, or sores
- Your symptoms don’t improve after home treatment
Getting an accurate diagnosis and prompt treatment is important to avoid complications and transmission to close contacts. Prescription medication is often needed to fully eliminate the infestation. Delaying medical care raises the risk of complications and spread to others.
Can scabies be prevented?
You can lower your risk of getting scabies by:
- Avoiding direct, prolonged, skin-to-skin contact with anyone who has scabies
- Not sharing clothing, towels, bedding, and furniture if someone in your house has scabies
- Practicing good hand hygiene by washing hands frequently
- Keeping fingernails short to limit areas mites can burrow
- Wearing gloves when caring for someone who is infested
- Promptly treating those diagnosed with scabies
- Disinfesting living spaces and clothing after treatment
In crowded living sites like nursing homes, prisons, and shelters, mass drug treatment to eliminate scabies may be considered even if just some residents are infested to prevent ongoing transmission.
Conclusion
Scabies is a highly contagious skin infestation, but early diagnosis and treatment can prevent complications and the spread to close contacts. Be alert for symptoms like intense itching and rashes in typical locations such as between the fingers, wrists, and buttocks. See a doctor promptly if scabies is suspected to get appropriate testing and medication. With the right treatment, most cases of scabies can be cured and prevented from recurring.