Diatomaceous earth (DE) is a naturally occurring substance derived from the fossilized remains of diatoms, which are microscopic aquatic organisms. Scabies is a skin infestation caused by tiny mites that burrow into the skin. This article explores whether diatomaceous earth offers an effective solution for scabies infestations.
Understanding Diatomaceous Earth
Diatomaceous earth is primarily composed of silica from the fossilized remains of ancient diatoms. These remains accumulate over millions of years, forming deposits mined and processed into a fine powder. DE’s effectiveness against certain insects stems from its microscopic, abrasive particles. When insects with exoskeletons contact DE, the sharp edges abrade their protective outer layer, the cuticle. This physical damage causes fluid loss, leading to dehydration and death through desiccation.
Food-grade DE contains less than 1% crystalline silica and is considered safe for incidental human or animal contact. Filter-grade DE contains high levels of crystalline silica and is intended for industrial uses like filtration.
Scabies: The Infestation Explained
Scabies is a contagious skin condition caused by an infestation of the human itch mite, Sarcoptes scabiei var. hominis. These microscopic mites burrow into the upper layer of the skin, the stratum corneum, where they live, feed, and lay eggs. The most common symptoms include intense itching, particularly at night, and a pimple-like skin rash. This itching and rash result from an allergic reaction to the mites’ presence, their proteins, and their fecal material. Characteristic burrows, appearing as tiny, raised, grayish-white or skin-colored lines, may be visible on the skin, often between the fingers, on the wrists, elbows, or genitals. Scabies primarily spreads through direct, prolonged skin-to-skin contact and is not linked to poor hygiene.
Does Diatomaceous Earth Affect Scabies Mites?
While diatomaceous earth effectively kills many insects by physical desiccation, its efficacy against scabies mites on human skin is not supported by scientific evidence. Scabies mites burrow under the skin, residing within the stratum corneum, which shields them from surface-applied substances. This protected location means topical DE would not directly contact the mites or their eggs. No clinical trials or scientific studies demonstrate DE as an effective treatment for human scabies infestations. Relying on DE for scabies treatment can delay access to proven medical therapies, potentially worsening the infestation and increasing the risk of secondary bacterial infections due to persistent scratching.
Safety Considerations for Human Use
Using diatomaceous earth on human skin, especially for scabies, carries potential risks. The abrasive nature of DE can cause skin irritation, dryness, or minor abrasions. While food-grade DE is generally considered safe for incidental contact, it is not intended for direct application to the skin for pest control.
A significant concern arises from the inhalation of fine DE dust. Even food-grade DE can irritate the nose, nasal passages, and lungs if inhaled, leading to coughing or shortness of breath. Long-term or extensive inhalation, particularly of filter-grade DE with higher levels of crystalline silica, is associated with serious respiratory problems, including silicosis and lung damage.
Recommended Treatments for Scabies
Medically recognized treatments are available and effective for eradicating scabies infestations. Prescription topical creams are the primary course of action, with permethrin 5% cream being a common first-line treatment. This cream is applied to the entire body, typically from the neck down, and left on for several hours before washing off. A second application a week later is often recommended to ensure all newly hatched mites are eliminated.
Oral medications like ivermectin may be prescribed for widespread infestations, individuals who cannot use topical treatments, or those with crusted scabies. Ivermectin is effective against mites but not their eggs, necessitating repeat doses.
Beyond medication, environmental cleaning measures are important, such as washing all bedding, clothing, and towels in hot water and drying them on high heat to kill any mites or eggs.
Consulting a healthcare professional for diagnosis and appropriate treatment is important for effective scabies management.