Acariasis

Acariasis

Acariasis is a condition caused by infestation with mites, which are small arthropods belonging to the subclass Acari. Mites are closely related to ticks and are found in a variety of environments, including soil, water, and as parasites on plants and animals. Acariasis can affect humans, domestic animals, and wildlife, leading to a range of clinical manifestations depending on the species of mite involved.

Etiology

Acariasis is caused by various species of mites. Some of the most common mites that cause acariasis in humans include:

• Sarcoptes scabiei: This mite causes scabies, a contagious skin condition characterized by intense itching and a pimple-like skin rash.
• Demodex spp.: These mites are part of the normal skin flora but can cause demodicosis when they proliferate excessively, leading to skin conditions such as rosacea.
• Trombiculidae: Also known as chiggers, these mites can cause intense itching and dermatitis.

In animals, acariasis can be caused by mites such as:

• Otodectes cynotis: The ear mite, which commonly affects cats and dogs, leading to otitis externa.
• Psoroptes spp.: These mites cause psoroptic mange in livestock.
• Sarcoptes scabiei: Also affects animals, causing sarcoptic mange.

Pathophysiology

The pathophysiology of acariasis varies depending on the mite species and the host's immune response. Mites can cause direct damage to the skin by burrowing or feeding, leading to inflammation and irritation. The host's immune response to mite antigens can also contribute to the clinical symptoms, such as itching and rash.

In some cases, mites can act as vectors for other pathogens, transmitting diseases such as rickettsialpox or scrub typhus.

Clinical Manifestations

The clinical manifestations of acariasis depend on the mite species and the host. Common symptoms include:

• Itching: Often severe and worse at night.
• Rash: May appear as papules, vesicles, or pustules.
• Secondary infections: Due to scratching and skin barrier disruption.

In animals, symptoms may include:

• Hair loss
• Thickened skin
• Ear discharge

Diagnosis

Diagnosis of acariasis is based on clinical examination and identification of mites. Techniques include:

• Skin scraping: To collect mites for microscopic examination.
• Dermatoscopy: To visualize mites in the skin.
• Biopsy: In some cases, to confirm the diagnosis.

Treatment

Treatment of acariasis involves eliminating the mites and managing symptoms. Options include:

• Topical scabicides: Such as permethrin or ivermectin.
• Oral medications: Ivermectin may be used for systemic treatment.
• Antihistamines: To relieve itching.

In animals, treatment may involve topical or systemic acaricides and supportive care.

Prevention

Preventive measures include:

• Good hygiene: Regular washing of clothing and bedding.
• Avoiding contact: With infested individuals or animals.
• Environmental control: Reducing mite habitats in homes and farms.

Also see

• Scabies
• Demodicosis
• Mange
• Rickettsialpox
• Scrub typhus