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[Microbiology](https://durgical.com/en/microbiology/) · [Ectoparasites](https://durgical.com/en/microbiology/groups/ectoparasites/)

# Tunga penetrans

- Parasite
- For completeness

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.

Updated 2026-11-01

Also called: chigoe flea, jigger, sand flea

## Key points

- A flea that penetrates bare feet, mostly around the nails.
- Whitish nodule with a central black dot.
- Risk of superinfection and tetanus.
- A zoonosis tied to extreme poverty and earthen floors.
- Sterile extraction and topical dimeticone.

## At a glance

**Shape**
Whitish nodule with a central black dot (the flea's rear end)

**Family**
Tungidae

**Type**
Insect: flea (Siphonaptera), ectoparasite

**Size**
Flea about 1 mm; the gravid female grows to about 1 cm in the skin

## Morphology

- Only the fertilised female penetrates the skin.
- It leaves its rear end exposed to breathe, defecate and expel eggs.
- Its abdomen swells enormously inside the epidermis.

## Transmission

- Walking barefoot on sandy or earthen ground where the larvae develop.
- Earthen floors in homes and animal pens.
- Not spread from person to person.

**Reservoir:** Pigs and cattle in rural areas; Dogs, cats and rats in poor urban neighbourhoods; Sandy or earthen soil

### Isolation precautions

What the care team adds to standard precautions.

- Standard

## Life cycle

- The fertilised female penetrates the skin, usually between the toes or under the toenails.
- It anchors head-down and leaves its rear end exposed to breathe and expel eggs.
- Its abdomen grows to about 1 cm and expels about 100 eggs over two weeks; then it dies.
- In sandy soil the eggs hatch in 3–4 days; the larvae feed on organic debris.
- After two larval stages they pupate in sand-covered cocoons; development takes 3–4 weeks.
- Adults emerge and seek a warm-blooded host: person, pig, dog, cat or rat.

## Virulence factors

- The embedded flea causes intense inflammation, pain and itch.
- Lesions ulcerate and become infected; there is a risk of tetanus and gangrene.
- Repeated infestation deforms toes, causes nail loss and makes walking hard.
- Removal with non-sterile objects can spread infections.

## Diseases it causes

- Tungiasis [Tungiasis and furuncular myiasis →](https://durgical.com/en/conditions/tungiasis-and-furuncular-myiasis/)

## Clinical picture

- Whitish papule or nodule with a central black dot on the toes, nail folds or heel.
- Pain and itch; difficulty walking.
- Multiple infestations in children and older adults in poor communities.

## Diagnosis

- Clinical diagnosis from the typical lesion on the foot.
- Finding the flea and its eggs in the lesion.

## Treatment

Sterile extraction of the flea by trained staff, wound care and a tetanus check; topical dimeticone is an effective and safe treatment. Antibiotics for superinfection.

Drug class only; doses and regimens are set by the clinician from the current guideline.

## Prevention

- Wear closed shoes.
- Seal or cement earthen floors and treat them with insecticide.
- Daily foot washing with soap.
- Treat infested animals (One Health).

## In Colombia

The 'nigua' is seen in rural and Indigenous communities with earthen floors, especially in barefoot children; it is a marker of extreme poverty.

## Memory aid

In it goes, up it swells: a black dot on a bare toe that grows into a lentil-sized lump.

## Test yourself

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

## Where is tungiasis typically found?

On the feet, between the toes and under or beside the nails, from walking barefoot.

## What does a Tunga penetrans lesion look like?

A whitish nodule with a central black dot, which is the flea's rear end.

## Which serious infection must be prevented in tungiasis?

Tetanus, as well as bacterial superinfection.

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## Related

- [Sarcoptes scabiei](https://durgical.com/en/microbiology/sarcoptes-scabiei/)
- [Dermatobia hominis](https://durgical.com/en/microbiology/dermatobia-hominis/)

## Related conditions

- [Tungiasis and furuncular myiasis](https://durgical.com/en/conditions/tungiasis-and-furuncular-myiasis/)

## What the colours mean

**Gram-positive**
Thick peptidoglycan wall: stains purple.

**Gram-negative**
Thin wall with an outer membrane: stains pink.

**Acid-fast**
Lipid-rich wall (mycobacteria): Ziehl–Neelsen stain.

[← Back to the group: Ectoparasites](https://durgical.com/en/microbiology/groups/ectoparasites/)

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

Sources: [CDC - DPDx - Tungiasis](https://www.cdc.gov/dpdx/tungiasis/index.html) (CDC, 2017); [Tungiasis](https://www.who.int/news-room/fact-sheets/detail/tungiasis) (WHO, 2023).

## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake

Representative model, for educational purposes only.

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License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/microbiology/tunga-penetrans/