What Are Sand Flea Bites?

Introduction

Sand flea bites are itchy, red bumps on your skin caused by insect bites. Sand fleas, sometimes called sand flies or beach fleas, are different species. Sand fleas come from the family Talitridae, which includes more than 60 terrestrial crustaceans known for their hopping ability. Meanwhile, sand flies belong to the family Psychodidae and can cause diseases that affect internal organs and skin. Sand fleas, such as Tunga penetrans, cause a disease called tungiasis, a zoonotic parasitic condition that targets the skin. It is important to understand the impact of sand flea bites, as tungiasis disproportionately affects individuals under 15 years old, the disabled, and the elderly.¹  

Characteristics of sand fleas

Sand fleas are 1.5 cm in length and typically live on sandy beaches. They prefer to be buried in the sand during the daytime but emerge at night to find food. They also thrive in humid conditions. The most common sand flea is Platorchestia platensis, which is found along the coasts of Europe, America, and Uruguay. This particular sand flea is brown with a blue tail and has reddish-brown antennae.²  

Another species in this family is Tunga penetrans (T. penetrans). According to the World Health Organization, over 1 billion people are at risk of contracting tungiasis, a disease caused by T. penetrans, in tropical and subtropical regions of the Caribbean, sub-Saharan Africa, and South America due to inadequate surveillance. The reported prevalence of tungiasis is inconsistent, ranging from 7% to 63%, making the burden of the disease difficult to determine. T. penetrans is less than 1 mm in length, making it the smallest known flea.¹ 

Life cycle and transmission and sand fleas

For sand fleas like T. penetrans and T. trimamillata, the life cycle lasts approximately one month. Interestingly, it is the unfertilized female that penetrates the skin and remains there, eventually dying after four to six weeks. During this time, the female sand flea expands up to 2000 times in size as the eggs develop and are expelled within 250 to 500 µm in the skin, marking the entry point for pathogens. The eggs develop into larvae within a maximum of six days, then into pupae in five to seven days, and ultimately into adults. The transformation from puparium to adult flea takes nine to fifteen days.

The main reservoirs for sand fleas are animals such as pigs, sheep, dogs, and cats; however, this can vary by country. Other modes of transmission can occur without an animal reservoir. Individuals may come into contact with sand fleas in soil or poor environmental settings. For example, those who sleep on the floor may contract tungiasis. Additionally, in rural areas of Africa, classrooms with poor flooring have a high chance of harbouring sand fleas. Children in these areas are more likely to contract the disease, as most do not wear closed shoes, allowing the sand flea to target the skin easily.⁴ 

Signs and symptoms of tungiasis

The symptoms of tungiasis can occur at any age, so knowing the signs and symptoms is crucial for a clearer medical diagnosis. 

• Lesions typically appear on the ankles, feet, soles, toes, and under the toenails.⁵ 
• Lescios can also be found on the backs, elbows, and fingers of patients who have slept on the floor.⁶ 
• Skin lesions may appear dark blue to blackish or yellow.⁷
• Individuals may also experience a loss of nails.
• Tungiasis can impact children's cognitive abilities.

Initially, symptoms are mild, but as the condition progresses, individuals may notice itching and swelling due to the expanding female flea. Pain when walking is also a common symptom. Complications from the lesions can include the risk of tetanus, which should be taken into consideration.⁷ 

Complications of tungiasis

Some individuals who contract tungiasis are at risk of further complications. This includes

• Tetanus, 
• Bacteremia which could lead to sepsis,
• Gangrene, or
• Secondary infections can occur such as enterobacteria, Staphylococcus aries, Clostridium spp, and Peptostreptococcus spp.⁸

Prevention and treatment for sand flea bites

In rural, endemic areas where sand fleas are prevalent, treatment options are often limited. Therefore, prevention becomes paramount. People typically rely on chemical agents such as kerosene or insecticides to kill sand fleas and prevent infestations.⁹ 

Unfortunately, there is no standard treatment for tungiasis. The World Health Organization (WHO) recommends surgical removal of the embedded fleas using a sterile needle. However, this approach presents challenges, particularly in rural areas where sterile conditions may be lacking, leading to a higher risk of bacterial infections. In such settings, individuals may resort to makeshift tools such as hairpins, sticks, sewing needles, or scissors, further increasing the risk of contracting diseases such as Human Immunodeficiency Virus (HIV), Hepatitis B Virus (HBV), and Hepatitis C Virus (HCV).¹⁰ 

Another method for treating tungiasis involves a two-component dimethicone, considered the 'gold standard' in treatment. However, this option faces challenges in accessibility, particularly in endemic areas, due to its associated financial costs. Alternative treatments, such as thiabendazole and metrifonate, are available, although they may not be as highly effective as dimethicone.¹¹ 

When travelling to regions with a high risk of tungiasis, it's essential to take preventive measures. Wear closed-toe shoes and long pants to minimize the risk of sand flea bites. Additionally, consider using insecticides, such as Zanzarin^Ⓡ, which is plant-based and can be sprayed on your feet. It's recommended to apply it twice a day for optimal protection.¹¹

Public health implications

In endemic settings, adopting a so-called ‘One Health approach’ is crucial for effectively managing this zoonosis and minimizing its detrimental effects on public health, animals, and the environment. Developing and implementing a strategic plan is essential to facilitate this approach. Figure 1 illustrates the One Health Approach. Since tungiasis is a neglected skin disease, it is imperative to identify key developmental areas that require attention to provide better resources and healthcare to those living in extreme poverty, as outlined in Table 1.

Figure 1 Venn diagram of the One Health approach. The One Health approach must take into consideration the three categories for strategies to work.

Table 1 Key developmental areas that should be considered, as well as the justification and resources required.¹²

Summary

In summary, sand flea bites can vary in severity and can lead to tungiasis, particularly in areas with extreme poverty and limited education on prevention methods. The characteristics and life cycle of sand fleas contribute to health risks, including secondary infections. Raising awareness of neglected skin diseases is crucial.

Due to unreliable data on disease incidence and prevalence, standardized treatment and prevention measures are lacking. However, strategies such as wearing closed-toe shoes and using insecticides can reduce the risk of tungiasis. Adopting a One Health approach could offer a clear strategy for addressing key areas needed to combat this zoonotic disease, including research, awareness campaigns, and surveillance, empowering communities to take preventive measures.

Overall, tungiasis requires further research and concerted efforts to improve healthcare in endemic regions. By addressing this neglected skin disease, we can enhance healthcare for individuals, as well as promote the well-being of animals and the environment. Improving health equity in developing nations remains a crucial goal.

FAQ’s

How do you know if you have sand flea bites?

You will know if you have sand flea bites if you notice small red bumps on your skin.

How do you know if you have sand fleas under your skin?

You will not know when the female sand flea has entered your skin as it takes 15 days for the larvae to turn into an adult. You may notice a black dot on your skin. 

Are sand fleas and sand flies the same thing?

Many people often use these two species interchangeably, however they are entirely different species from different families.