Skin disease in tropical travelers

National report - Skin disease is one of the main reasons for consultation in travelers returning from the tropics, according to Eric Caumes, M.D., professor of infectious diseases and dermatologist in the department of infectious and tropical diseases at Hospital Pitié-Salpêtrière in Paris.

Dr. Caumes and colleagues examined 632 health problems in 622 travellers returning from the tropics. The most common health problems reported in that population were dermatoses, with 149 cases (23.4 percent), followed by gastrointestinal problems (122 cases, or 19.1 percent) and respiratory disorders (73 cases, or 11.5 percent).

Delayed treatment

For example, in an earlier study of localized cutaneous leishmaniasis in American patients, investigators reported a median time of 112 days between appearance of cutaneous lesions and delivery of treatment, with one patient waiting more than two years before receiving appropriate treatment. In another French study, most patients with cutaneous larva migrans had already consulted, on average, two other doctors before seeking treatment at a travel clinic.

Most common dermatoses

In a two-year prospective study of travel-related skin diseases that Dr. Caumes and colleagues conducted in the 90s, the most common disease was cutaneous larva migrans, followed by bacterial skin infections, arthropod-related pruritis, and myiasis.

Other diseases, such as tungiasis and scabies, were seen in less than 10 percent of the patients. Fifty-two percent of skin diseases in this study were of tropical origin.

Ten years later the study was repeated, with slight differences. Migrants and long-term residents were included in the study population, and the study covered six months, rather than two years. The top nine dermatoses observed were infectious cellulitis, scabies, pruritus of unknown origin (PUO), pyoderma, myiasis, tinea, filariasis, cutaneous larva migrans and urticaria. Notably, tropical disease accounted for only one-third of the skin diseases in the returning travelers, compared to over half of the diseases reported ten years earlier. Significant associations were noted between infectious cellulitis and female gender (p=0.03), between PUO and immigrant status (p<0.0001) and older age (p=0.01), between myiasis and tourism (p=0.02) and travel to Africa (p=0.05), between filariasis and travel to Africa (p=0.0001) and immigrant status (p=0.0001) and between cutaneous larva migrans and tourism (p=0.01).

Bacterial infections

Cutaneous bacterial infections may be the most important cause of skin disease in returning travelers.

Patients can present with impetigo, usually related to an insect bite or sting, or with erysipela, abscess, carbuncle, intertrigo, folliculitis or necrotizing cellulitis.

"Bacterial infection is a real problem. Patients who are at risk for bacterial skin infection should carry with them an antibiotic effective against streptococcal and staphylococcal skin infections," Dr. Caumes advises.

Creeping eruptions

Creeping eruption is a cutaneous sign, whereas cutaneous larva migrans is a syndrome, and not a specific disease (Lancet Inf Dis 2004; 4: 659-660).

Creeping eruption may be due to subcutaneous migration of a parasitic larva, as in hookworm-related cutaneous larva migrans, or to migration of adult parasites, as in scabies or myiasis. Other types of creeping eruption, such as lichen striatus, may be unrelated to parasitic infection.

Hookworm-related

Travelers coming back from a tropical beach resort may have cutaneous larva migrans, which presents as a creeping eruption, in relation to the subcutaneous migration of a hookworm larva.

"Usually the disease appears during travel," Dr. Caumes says. "When it appears after travel, the median time between return and appearance of cutaneous lesions is approximately one to two weeks. It never exceeds four months."

Normally there is one cutaneous track per patient, although there can be more. Because cutaneous larva migrans is highly pruritic, bacterial infection is common.