A recent study found that skin disease affects up to 8% of travelers. Skin disease is the third most common problem of travelers, after diarrhea and respiratory disorders. It is worthwhile for all health care providers to have a passing familiarity with the major cutaneous diseases that occur in travelers. Although this chapter can only address the issue in a limited fashion, the Centers for Disease Control and Prevention (CDC) has an interactive website where patients and clinicians can enter a travel destination to access country-specific health advisories ( wwwnc.cdc.gov/travel ).
Cutaneous larva migrans
Soft tissue bacterial infections
Allergic reaction or urticaria
Superficial fungal infection
Injuries including animal bites
Important History Questions
Where have you traveled recently?
Some diseases are common in certain areas of the world. For example, leishmaniasis is encountered in persons traveling to Central and South America or the Middle East. Myiasis is common in persons traveling to Central and South America or parts of Africa. Even some US territories, such as Puerto Rico, may be affected by diseases, such as Zika virus or chikungunya virus, which can cause a viral exanthem.
Did you develop skin disease before you traveled, while traveling, or after you returned home?
It is important to understand the timeline of disease activity. Some skin disease in the traveler represents aggravation of a preexisting condition, such as atopic dermatitis. Other conditions, such as urticaria and other allergic reactions, can develop during travel simply because of exposure to an allergen. Finally, some conditions such as myiasis and leishmaniasis are notorious for developing in the weeks and months after travel.
Were you outdoors or in a rural area during your travels?
Some diseases, such as leishmaniasis and myiasis, are caused by the bite of flying insects, and determining whether the patient has been outdoors is important (e.g., hiking, camping). Cutaneous larva migrans is a disease associated with exposure to beach sand contaminated with cat or dog feces. Tungiasis, caused by the bite of the sand flea, is also acquired on beaches.
On your trip, did you use preventive measures to avoid disease?
The use of insect repellents, bed netting, and/or sleeping in screened areas with environmental controls are measures that lessen the likelihood of a traveler acquiring some cutaneous diseases. Avoiding direct contact with contaminated beach sand is another measure. For some diseases, such as yellow fever, there is a vaccine for those traveling to endemic areas.
Cutaneous Larva Migrans
ICD10 Code B76.9
Where and How
Cutaneous larva migrans (CLM) is a parasitic skin infection caused by the hookworms Ancylostoma braziliense and Ancylostoma caninum , which affect the intestines of cats and dogs. Humans are infected with CLM larvae by placing their bare skin (e.g., feet, hands, buttocks) in contact with sand contaminated by animal feces. The larvae penetrate human skin, but cannot complete a full life cycle. The organism migrates under the skin surface, leading to a so-called creeping eruption. CLM occurs in travelers from sub-Saharan Africa, Asia, Central and South America, and the Caribbean. Some cases occur in the United States, on the Gulf Coast, but use of anthelmintic agents in pets has greatly reduced the rate of endemic acquisition.
CLM causes an erythematous pruritic eruption that migrates (or creeps) under the skin ( Fig. 36.1 ; also see Fig. 17.15 , Fig. 17.16 , Fig. 17.17 , Fig. 17.18 ). The condition usually begins days or weeks after exposure, but larva can lie dormant for months before migrating. Excoriation can yield ulceration, with secondary infection. The lesions affect skin exposed to sand, such as the hands, feet, and buttocks. The tracks may advance a few millimeters to several centimeters each day.
The diagnosis of CLM is based on an appropriate travel history and characteristic clinical appearance. Confirmation by biopsy is challenging because the organism is always migrating ahead of the host response.
Prevention and Treatment
Prevention includes wearing shoes in areas of contaminated sand. Many communities ban dogs from beaches for this reason. Oral agents for CLM include albendazole, mebendazole, and ivermectin. Thiabendazole can be used as a topical cream or systemic (oral) agent. Destructive modalities (e.g., liquid nitrogen) are problematic because the organism lies ahead of any visible inflammatory response.
ICD10 Code B87.9
Where and How
Myiasis is a disease caused by the parasitic infestation of the human body with fly larvae. There are different forms of myiasis, but the two types we will concern ourselves herein with are caused by Dermatobia hominis (the human bot fly) and Cordylobia anthropophaga (the tumbu fly). Bot fly myiasis is seen throughout Central and South America; the fly larva is placed on the skin by mosquitoes in a complex life cycle interplay. Tumbu fly myiasis is seen in Africa ( Fig. 36.2 ); it is caused by clothing and linens hung outdoors, where flies lay eggs on the fabric and that are later in contact with skin.
Myiasis is caused by fly larva burrowing into the skin and maturing there, leading to an expansive nodule. In myiasis, affected persons often complain of a cyst or bump that is associated with a moving sensation. The lesion may grow over weeks or months but, eventually, to complete the life cycle, matured larva must exit the skin to become mature insects. Because the organism must respire, often the nodule is seen to have a central punctum, or breathing hole.
The diagnosis of myiasis is usually established by a travel history of outdoor exposure at the destination of interest and a clinical situation of a nodule or dermal abscess, often with a central punctum and with the sensation of movement.
Prevention and Treatment
Prevention of bot fly myiasis includes avoiding biting insects in an outdoor environment and the use of bed netting when sleeping outdoors. Prevention of tumbu fly myiasis includes ironing clothing and sheets hung outdoors. Although there are regional treatments for myiasis used by persons in an endemic area, such as bacon fat poultices, excision is the treatment of choice for imported cases of myiasis seen in the United States.