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[Microbiology](https://durgical.com/en/microbiology/) · [Parasites](https://durgical.com/en/microbiology/#d-parasite)

# Ectoparasites

- Parasites

Arthropods living on or in the skin: the scabies mite, lice, the chigoe flea and fly larvae that cause myiasis.

Updated 2026-11-01

## What they are

Ectoparasites are arthropods (mites and insects) that feed on the host's skin or blood. They are linked to poverty, crowding and lack of shoes or water, and besides discomfort they cause bacterial superinfection and, in the case of the body louse, transmit disease.

## What they share

- Arthropods: mites (Sarcoptes) and insects (lice, fleas, flies).
- Live on or in the epidermis.
- Linked to crowding, poverty and lack of shoes.
- Scratching and wounds open the way to bacterial infection.

## Key points

- Scabies and pediculosis need contact precautions.
- Treat all contacts at once in scabies and pediculosis.
- Only the body louse transmits disease (typhus, trench fever, relapsing fever).
- Chigoe flea and myiasis: remove the parasite and care for the wound.
- Impetigo after scabies can lead to post-streptococcal glomerulonephritis.

## Microorganisms in this group

- [**Sarcoptes scabiei** A tiny mite that burrows into the skin and causes intense itch, worse at night. It spreads by skin-to-skin contact and affects whole families. Exam priority: high](https://durgical.com/en/microbiology/sarcoptes-scabiei/)
- [**Pediculus humanus and Pthirus pubis** Head, body and pubic lice: wingless blood-sucking insects. Only the body louse spreads diseases such as typhus. Exam priority: medium](https://durgical.com/en/microbiology/pediculus-humanus-and-pthirus-pubis/)
- [**Tunga penetrans** A sand flea that burrows into the skin of bare feet, usually beside the toenails, and swells into a small lump with a black dot. For completeness](https://durgical.com/en/microbiology/tunga-penetrans/)
- [**Dermatobia hominis** Fly larvae living in skin or wounds. The botfly sends its eggs on a mosquito, and its larva forms a boil-like lump with a breathing hole. For completeness](https://durgical.com/en/microbiology/dermatobia-hominis/)

## Test yourself

Think of the answer, then tap the question to see it.

## Which ectoparasitic infestations need contact precautions in hospital?

Scabies and pediculosis.

## Which ectoparasite transmits epidemic typhus?

The body louse (Pediculus humanus corporis).

## What do tungiasis and myiasis share in treatment?

Both are treated mainly by removing the parasite and caring for the wound.

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Educational content on microorganisms; not a treatment guide and no substitute for a health professional's advice. No doses are given.

Sources: [Scabies](https://www.who.int/news-room/fact-sheets/detail/scabies) (WHO, 2023); [About Lice | Lice | CDC](https://www.cdc.gov/lice/about/index.html) (CDC, 2024); [Tungiasis](https://www.who.int/news-room/fact-sheets/detail/tungiasis) (WHO, 2023); [CDC - DPDx - Myiasis](https://www.cdc.gov/dpdx/myiasis/index.html) (CDC, 2024).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/microbiology/groups/ectoparasites/
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