Scabies: Symptoms, Causes and Treatment

Scabies is a highly contagious skin condition caused by the infestation of the skin by the human itch mite, Sarcoptes scabiei var. hominis. This condition affects millions of people worldwide, causing intense itching and discomfort. Understanding the symptoms, causes, types, and treatment options for scabies is crucial for effective management and prevention.

Symptoms of Scabies

The primary symptoms of scabies are intense itching and a pimple-like rash. These symptoms result from the body’s allergic reaction to the mites, their eggs, and their waste. The itching is often worse at night and can be severe enough to interfere with sleep.

1. Itching: The hallmark symptom of scabies, which typically worsens at night.
2. Rash: A pimple-like rash that may include tiny blisters and scales. The rash can appear on various parts of the body, including between the fingers, wrists, elbows, armpits, waist, and buttocks.
3. Burrows: Thin, wavy, thread-like lines on the skin that are the tracks created by the mites as they burrow and lay eggs. These burrows are often found in the webbing between the fingers and toes, as well as the folds of the wrist and elbow.
4. Sores: Scratching the affected areas can lead to sores, which may become infected with bacteria, causing additional complications such as impetigo.
5. Thickened skin: In severe or prolonged cases, the skin can become thickened and scaly.

Causes of Scabies

Scabies is caused by the Sarcoptes scabiei var. hominis mite. The mite is a microscopic parasite that burrows into the upper layer of the skin, where it lives and lays its eggs. The primary mode of transmission is through direct, prolonged, skin-to-skin contact with an infected person. Scabies can also spread through infested bedding, clothing, and furniture, though this is less common.

Several factors can increase the risk of contracting scabies:

1. Close physical contact: Living in crowded conditions, such as nursing homes, child care centers, and prisons, can facilitate the spread of scabies.
2. Sexual contact: Scabies can be transmitted through sexual contact, making it a concern in sexually active individuals.
3. Compromised immune system: Individuals with weakened immune systems, such as those with HIV/AIDS or undergoing immunosuppressive therapy, are at higher risk of severe scabies infestations.

Types of Scabies

There are several types of scabies, each with distinct characteristics:

1. Classical scabies: The most common form, characterized by intense itching and a pimple-like rash. It typically affects the hands, wrists, elbows, and other common areas.
2. Nodular scabies: This type of scabies results in the formation of itchy, firm, red nodules on the skin. These nodules can persist even after the mites have been eradicated.
3. Crusted (Norwegian) scabies: A severe form of scabies that occurs in individuals with compromised immune systems. It is characterized by thick, crusted lesions containing thousands of mites and eggs. Crusted scabies is highly contagious and requires aggressive treatment.
4. Scalp scabies: Although less common, scabies can affect the scalp, particularly in infants and young children. It presents with itching and rash on the head and neck.

Treatment of Scabies

Effective treatment of scabies involves eliminating the mites and managing symptoms. Several treatment options are available:

1. Topical medications: The primary treatment for scabies involves prescription topical medications called scabicides. These include:
   • Permethrin cream: A commonly prescribed scabicide that is applied to the entire body from the neck down and left on for 8-14 hours before being washed off. A second application is often recommended one week later.
   • Lindane lotion: An alternative scabicide, but it is less commonly used due to potential neurotoxic side effects, especially in children and pregnant women.
   • Crotamiton cream or lotion: Another option for treating scabies, applied in a similar manner to permethrin.
   • Sulfur ointment: A treatment option for infants, pregnant women, and individuals who cannot tolerate other scabicides.
2. Oral medications: In cases of crusted scabies or when topical treatments fail, oral ivermectin may be prescribed. This medication is taken as a single dose, with a second dose given one to two weeks later.
3. Antihistamines: Over-the-counter or prescription antihistamines can help alleviate itching and improve sleep.
4. Antibiotics: If secondary bacterial infections develop due to scratching, antibiotics may be necessary to treat the infection.
5. Environmental decontamination: To prevent re-infestation, it is crucial to wash all bedding, clothing, and towels used by the infected person in hot water and dry them on high heat. Items that cannot be washed should be sealed in plastic bags for at least 72 hours. Vacuuming furniture and carpets can also help remove mites.

Prevention of Scabies

Preventing the spread of scabies involves several key measures:

1. Avoid close contact: Minimize skin-to-skin contact with individuals known to have scabies until they have completed treatment.
2. Treat household members: Close contacts and household members of an infected person should be treated simultaneously to prevent re-infestation.
3. Maintain hygiene: Regularly wash and change bedding, clothing, and towels.
4. Isolate infested items: Items that cannot be washed should be isolated in plastic bags to kill any remaining mites.

Conclusion

Scabies is a distressing but treatable condition caused by the human itch mite. Understanding the symptoms, causes, types, and treatment options is essential for effective management and prevention. Prompt diagnosis and treatment can alleviate symptoms and prevent the spread of scabies to others. If you suspect you have scabies, it is important to seek medical advice and follow the prescribed treatment regimen to ensure a complete recovery.