No, there is no single shot for scabies
Scabies is typically treated with topical creams or oral medications, not a single injection. These medications, called scabicides, are designed to eliminate the Sarcoptes scabiei mites and their eggs. While injections are not standard for general scabies treatment, in rare cases of nodular scabies, a specific steroid injection might be used for persistent itchy nodules after the mites are gone.
The primary treatment methods
Treatment choice depends on infestation severity, patient age, and other health factors. Doctors consider efficacy, safety, and cost.
Topical cream treatment: Permethrin
Permethrin 5% cream is the preferred initial treatment for most standard scabies cases. This topical agent is a safe and effective synthetic pyrethroid.
How to use permethrin cream:
- Apply thoroughly to all skin surfaces from the neck down, including the scalp, temples, and face for infants and the elderly, avoiding the eyes.
- Leave the cream on for a specified duration before washing it off, as directed by a healthcare professional or product instructions.
- A second application after a recommended interval is often advised to kill any mites that have hatched since the initial treatment.
Oral tablet treatment: Ivermectin
Oral ivermectin may be used for severe infestations, outbreaks in institutions, or when topical treatments are impractical. It is not FDA-approved for scabies but is recommended by the WHO and used off-label in many countries.
How to use ivermectin tablets:
- The appropriate amount is based on body weight and typically given in multiple administrations separated by a specific timeframe.
- Taking it with food can improve absorption.
- Ivermectin is generally not recommended for pregnant or breastfeeding women or children under a certain weight.
Other scabies treatments
Alternative treatments are available for situations where primary options are unsuitable or ineffective.
- Sulfur ointment: A compounded sulfur ointment of a particular concentration is effective, particularly safe for infants under 2 months, although it is messy and has an odor.
- Benzyl benzoate: An effective topical lotion, but it can cause significant skin irritation and is not available in the U.S. for scabies.
- Crotamiton: Available as a cream or lotion and FDA-approved for adults, it's often less effective than permethrin.
- Spinosad topical suspension: Approved for patients aged 4 and older, this offers another topical option.
- Moxidectin: This oral medication is being evaluated and may require fewer administrations due to its longer half-life.
Comparison of treatments
| Feature | Permethrin 5% Cream | Oral Ivermectin (Tablets) |
|---|---|---|
| Application | Topical, applied to the entire body. | Systemic, taken by mouth. |
| Primary Use | First-line treatment for most standard scabies cases. | Alternative for standard scabies; often combined with a topical for crusted scabies. |
| Application/Dose | Single overnight application; often repeated after a specified interval. | Administered in multiple doses over a period of time. |
| Kills Mites | Yes. | Yes. |
| Kills Eggs | Yes, also ovicidal. | No, not ovicidal; hence the potential need for multiple doses. |
| Special Populations | Safe for infants ≥2 months and pregnant/breastfeeding women. | Not recommended for pregnant/breastfeeding women or children <15 kg. |
Environmental and lifestyle management
Treating the infected person is only one part of successful scabies eradication. To prevent re-infestation, it is crucial to address the wider environment and any close contacts.
- Treat all contacts: All household members and other close contacts should be treated simultaneously, even if they don't have symptoms, as they may be infested but asymptomatic.
- Wash linens and clothes: All bedding, clothing, and towels used within the last week should be washed in hot water (at least 50°C or 122°F) and dried in a hot dryer.
- Handle non-washable items: Items that cannot be washed can be sealed in a plastic bag for at least 72 hours, as mites can survive off a human host for only a few days.
- Address post-treatment itching: It is common for itching and rash to persist for up to four weeks after successful treatment, as this is a reaction to the dead mites and mite debris. This does not mean the treatment has failed. Calamine lotion or oral antihistamines can help manage the itch.
Conclusion
In summary, there is no single injection available for the standard treatment of a scabies infestation in humans. Instead, medical professionals prescribe topical creams like permethrin or oral tablets like ivermectin, which are highly effective when used correctly. For complete eradication, all close contacts must be treated and environmental controls, such as laundering fabrics, must be implemented. A doctor's diagnosis and adherence to the prescribed treatment plan are essential for managing scabies effectively and preventing its spread.
For more detailed clinical information on scabies management, visit the Centers for Disease Control and Prevention (CDC) website.
