**5. Conclusions**

sensitized with respect to parasites that may lead the development of the strong specific

Diagnosis is based on the clinical manifestations, taking into consideration the history of being in contact with vegetation and the seasonality. As the etiological agent of the trombiculiasis is rarely found in the skin of the patients, these reactions are often misinterpreted and has been wrongly associated to plant allergies, flea or mosquito bites, or even scabies [26]. Cutaneous findings are nonspecific, so clinical examination would probably lead to a wrong diagnosis of a nonspecific itchy dermatitis, leading to use inadequate or needless medications. Then an accurate anamnesis is essential for making such challenging diagnosis. Chigger bites should

be considered whenever any unexplained skin eruption is presented to the physician.

*autumnalis* in a man with a well-documented diagnosis of scabies [100].

(*Meadow dermatitis*) should be taken into consideration [26].

resulting from repeated scratching occurs.

for this purpose in the European Union [10,26].

infection.

Chiggers are not easily seen on human's skin with the naked eye, and common magnification lenses and even dermoscopy (×10 magnifications) have some limitations. Recently, videoder‐ matoscopy (×150 magnification) has been used to diagnose trombiculiasis caused by *N.*

Differential diagnosis includes infestations with other mite species (e.g., the itch mite *Sarcoptes scabiei*), or blood-sucking ectoparasites, such as bed bugs, fleas, ticks, and mosquitoes. Also, hypersensitivity to chemical substances or photoallergic skin reaction to contact with a plant

Treatment is primarily symptomatic and consists of antipruritics, antihistamines, and topical corticosteroids [112]. In our medical consultation, supportive measures such as oatmeal baths are also highly recommended. Antibiotics might be needed in case bacterial superinfection

After being in known areas of chigger activity, the dermatitis can be minimized, and the recovery time can be significantly shortened, by taking a hot soapy shower or bath and washing clothes with soap and hot water. These good practices are recommended immediately after exposure, in order to remove both unattached and attached chiggers, before they have firmly anchored to the skin (generally within 3–6 h following attachment) [1,26]. Once the papules are present, scratching should be avoided in order to prevent to excoriate the lesions and the

Patients should be advised on preventive measures, including avoidance of high-risk areas when larvae are active. Since in many cases these results are unreasonable and contact with trombiculid mites is unavoidable, chigger infestation may be minimized by wearing protective clothing and soaking socks and trouser legs with insect repellents [112]. Usually, the use of repellent sprays and lotions containing benzyl benzoate or diethyltoluamide has been recommended [29]. Permethrin was successfully used as a clothing treatment for personal protection against chigger mites [113]. However, the active ingredient is no longer available

inflammatory response [39, 111].

**3.3. Diagnosis and treatment**

192 An Overview of Tropical Diseases

Chiggers are worldwide distributed ectoparasites that have to be taken into account as human pathogens. Their medical importance is based on their role as vectors of scrub typhus and as causative agents of trombiculiasis.

Scrub typhus remains as one of the most life-threatening infection in Asian Pacific regions. The development of a prophylactic vaccine against *O. tsutsugamushi* is of great interest in endemic regions. In addition, special attention should be paid on recent reports of scrub cases typhuslike infections in unusual areas, and on reviewing the genetic diversity of the genus *Orientia*.

More research studies are necessary in order to clarify the relationship of chiggers with other bacterial or viral infections.

Trombiculiasis is an extended but underreported condition that should be considered when pruritic dermatitis in people exposed to vegetation occurs. In risky areas, personal protection is the unique recommendation to reduce the parasitation. A deeper understanding of chiggers' life cycle, epidemiology and seasonality of trombiculiasis is required for a correct management of this annoying dermatitis.
