Introduction

Tungiasis (tun-JAI-uh-sis) is a painful, itchy skin condition characterised by a rash of whitish discs that vary in size, with a whitish-yellow circle and black dot in the centre. It occurs when adult female sand fleas (Tunga penetrans) burrow into your skin to feed and lay eggs.^1,2 Tungiasis can occur in both animals and humans, and these lesions typically appear on the foot; however, they can develop anywhere on the body. The issues associated with tungiasis result from an inflammatory reaction around the embedded sand fleas, with swelling, pain and itching being common symptoms. Secondary bacterial infections of the lesions can lead to fissures, ulcers, lymphangitis or ascending neuritis, resulting in pain, disfigurement or mutilation of the feet.²

The first reports of tungiasis occurred in the 1500s, from members of Christopher Columbus’ crew, who likely picked up the fleas when shipwrecked in Haiti.³ This infection typically occurs in tropical, rural areas such as sub-Saharan Africa, South America, India, and Pakistan, with higher occurrence where access to healthcare and preventative measures are limited, and it has been reported that incidence amongst a population can reach 50%.⁴

The larvae and pupae of sand fleas (also known as chigoe fleas) develop in dry, shaded soils, and transmission to humans typically occurs in earthen or sandy areas, since the fleas prefer warm, dry environments such as beaches, farms or stables.^1,5 They are typically too small to see with the naked eye, and transmission can also occur through direct contact with animal fursuch as pigs, cows, dogs, cats and rats that have sand fleas.² Only female sand fleas cause the tungiasis rash, however, male sand fleas can also bite and feed on your blood. Males don’t cause tungiasis as they do not burrow into the skin to lay eggs. 

Transmission typically occurs through the ground; hence, wearing the correct type of footwear can prevent the disease, with studies conducted showing that there are approximately 58% lower odds of getting tungiasis when appropriate footwear is worn.⁶ This article discusses tungiasis, risk factors for it, and several preventative measures you can employ, with a focus on the importance of footwear. 

Symptoms

Initially, the burrowing of sand fleas is painless, and symptoms typically only develop after some time, once the females have grown bigger and start to form eggs.⁵ Most individuals affected tend to try and extract the fleas themselves, leaving the lesion with blackened remains of the dead flea.² Then, once the flea is embedded, it can cause various symptoms such as:¹

• Itching/irritation
• Difficulty walking, if there are multiple lesions in the feet
• Difficulty concentrating, affecting school or work due to severe itching and pain⁷
• Odema: Swollen or puffy areas of the skin that are shiny or stretched, discomfort when pressing on the skin, or when a pit can be left in the skin when pressed⁸
• Erythema: symmetrical, red, raised skin areas that can appear all over the body⁹
• Desquamation: peeling or flaking skin, leaving new skin underneath¹⁰
• Pain
• Abscesses: painful reddish lump on the skin that may leak pus¹¹

Sand flea life cycle

Signs of infection depend on the flea’s life cycle. Within the first stage, the parasite penetrates the epidermis layer (outermost layer of the skin), causing redness (erythema) and pain. After a few days (Stage 2), a dark dot appears as the parasite leaves its end outside of the skin. After feeding for a few days (Stage 3), the parasite enlarges as it grows hundreds of eggs, and the lesion becomes more visible. Once the eggs have been expelled after 5 weeks (Stage 4), the flea dies, and the lesion is covered with a black crust.¹²  After this, the host may be able to remove the parasite (Stage 5), but a round depression, or deepening in the skin, will be visible for a few months. Overall, the female flea increases its volume by up to 2000 times its original size, including producing hundreds of eggs that fall out of the lesion afterwards.¹³ 

Secondary infections

Typically, tungiasis causes discomfort and pain; however, secondary bacterial infections that arise after the tungiasis infection may prove to be more problematic than the tungiasis itself. These can include:

• Tetanus: a life-threatening bacterial infection that affects the nervous system¹⁴
• Ulcers: open wound or sore that will not heal or keeps returning¹⁵
• Abscess¹¹
• Cellulitis: A painful, hot and swollen area of the skin, may look red depending on skin tone, caused by a bacterial infection of the skin¹⁶
• Gangrene: a serious condition where a loss of blood supply causes body tissue to die, can result in black, red or purple skin in the area¹⁷
• Osteomyelitis: inflammation or swelling occurring in the bone, typically from a bacterial bloodstream infection¹⁸
• Thrombophlebitis: A condition that causes a blood clot to form and block one or more veins, often in the legs¹⁹

Diagnosis

Diagnosis is typically done through a simple examination of the skin.. However, it may be difficult to diagnose in travellers returning to their home country, where tungiasis is rare and clinicians are less experienced in the disease. A biopsy or dermascopy may also be done to help diagnose and to ensure all fragments of the flea have been removed, to prevent inflammation.¹³

Preventative measures and risks, including footwear

Tungiasis is typically more prevalent in children and the elderly, with its incidence declining during adolescence.² Several factors can increase the risk of infestation, including walking barefoot, due to the mode of infestation. A study conducted showed that houses located on dunes or with sandy floors were associated with significantly higher infestation rates.⁷ Additionally, other risks can include the improper disposal of waste or overcrowding of a household.⁷

Furthermore, another major risk factor is the presence of furry pets. Keeping animals away from living spaces can reduce the likelihood of tungiasis by up to 52%. Personal hygiene practices can also play a role, with the regular use of deodorant or body lotion post-bathing seeming to have a positive effect, reducing the likelihood of developing tungiasis.⁷ Furthermore, studies show that applying coconut-oil-based repellents twice daily, or even intermittently after bathing, appears to reduce the flea penetration.²⁰

Due to the limited jumping ability of the tunga flea, the most common infection site is the feet.²¹ Hence, the key amongst risk factors includes walking barefoot. Most individuals affected, especially children, either do not wear shoes regularly or wear open-toed footwear such as sandals or slippers, leaving their feet vulnerable to infestation. Studies indicate that consistent use of proper footwear can reduce infestation rates by nearly 50%.²² Closed-toe shoes act as a physical barrier, preventing fleas from penetrating the skin, especially in high-risk environments such as sandy or muddy floors. Some factors, however, influence the use of footwear in endemic regions:²²

• Economic barriers: Some individuals in affected areas cannot afford sturdy, closed-toe shoes. Even when shoes are available, they may be old, damaged, or uncomfortable for daily wear²²
• Cultural and behavioural factors: Some communities have traditional practices that discourage wearing shoes indoors or in certain social settings. Additionally, a lack of awareness regarding the role of footwear in disease prevention further reduces its adoption²²
• Environmental constraints: In hot and humid climates, wearing closed shoes for extended periods may cause discomfort, leading individuals to prefer open footwear or walking barefoot. Some studies suggest that prolonged use of enclosed footwear in such conditions can contribute to secondary skin conditions, including fungal infections and plantar maceration²²

Although the protective effect of footwear is well-documented, its effectiveness depends on consistent and proper usage. Many individuals in endemic areas wear shoes irregularly or remove them when inside their homes, where flea infestations are often present. Moreover, dirty feet and clothing have been linked to an increased risk of infestation, suggesting that hygiene practices must accompany footwear use for optimal protection.²²

Treatment

To reduce the incidence and tungiasis-associated morbidity once infected, one should ensure that, if possible, they visit a doctor, such as a dermatologist (for skin treatments), as soon as possible. The simplest therapy is extraction using a sterile needle.²³ However, in cases where the flea has become enlarged, surgical extraction of the flea under sterile conditions using sterile forceps or needles may be required.²⁴ In some cases, the entire lesion may need to be cut out. If the flea becomes torn, or some parts of the flea are left in the sore, this can cause inflammatory issues. The wound should be dressed appropriately. 

Another method of treatment is cryotherapy to freeze the skin tissue, killing the sand flea.²¹

If the flea has already been removed at home, this is typically done in non-sterile conditions and can be particularly painful for the person infected and can cause inflammation if the parasite ruptures or introduces secondary bacteria.²

One should also apply a topical antibiotic cream to prevent secondary bacterial infections and ensure that the person is appropriately vaccinated against tetanus.²¹ If not, anti-tetanus prophylaxis is provided, as this is a common infection co-occurring with tungiasis. One can also apply a thick wax or jelly to suffocate the flea.^12,21,25 One should continue daily inspection of the feet to protect against and identify further complications early.²⁶

Summary

Tungiasis is a parasitic skin disease caused by the female sand flea Tunga penetrans, which burrows into the skin, typically the feet, causing itching, pain, inflammation, and potential secondary infections like tetanus, cellulitis, or gangrene. It is common in tropical, rural regions, particularly where people walk barefoot in sandy or dry soil environments.

The disease mainly affects children and the elderly and is linked to poverty, poor hygiene, and proximity to animals. Prevention relies heavily on physical barriers like closed-toe footwear, which can reduce infection risk by nearly 50%. However, consistent use is hindered by economic, cultural, and environmental factors, such as discomfort in hot climates or lack of access to proper shoes. Regular hygiene, keeping animals away from living areas, and using repellents also help reduce risk.

Diagnosis is clinical but may require dermatoscopy or biopsy. Treatment includes sterile extraction, topical antibiotics, cryotherapy, and tetanus prophylaxis. Self-removal is risky and may lead to complications if done improperly.

Footwear remains a critical, low-cost intervention in preventing tungiasis, especially when paired with hygiene and environmental control strategies.