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Information

Editors

VilleHolmberg
HeliSiikamäki
MerjaKousa
TinjaLääveri

Skin Problems in Returning Travellers

Essentials

  • Skin problems are, after fever and diarrhoea, the third most common cause for visiting a doctor following foreign travel.
  • Reactions to insect bites as well as cutaneous bacterial and fungal infections are the most common skin diseases affecting a returning traveller.
  • Tropical climate and sunshine may worsen existing skin problems, such as rosacea and systemic lupus erythematosus.
  • Herpes infection of the face may be activated by strong sunlight.

Rashes associated with sunlight

Sunburn

  • A fair skinned Nordic person can have sunburn after 5-10 minutes sun exposure on the equator and after 20-30 minutes exposure on the Canary Islands during the winter months.
  • Symptoms do not emerge until 4-8 hours after the exposure to sunlight.The skin becomes red (picture 1), is tender to the touch and in severe cases oedema and blisters develop.

Polymorphous light eruption

  • The most common type of photodermatitis
  • Usually starts abruptly several hours after strong sun exposure.
  • Symptoms include severely pruritic papules and vesicopapules (picture 2).
  • Symptom duration varies from a few days to a few weeks.
  • In mild cases the skin's tolerance to the sun will gradually increase.

Phototoxic or photoallergic skin reaction

  • The skin is sensitised to ultraviolet radiation through exogenous chemical substances or internally taken medicines.
  • The most common causes of allergic photocontact dermatitis are substances used in the perfumes of cosmetics.
  • Phototoxic reactions associated with vesicle formation known as phytophotodermatitis (pictures 3 4) result from psoralens found in plants, particularly in members of the family Umbelliferae, burning bush (Dictamnus albus) and common fig (Ficus carica) as well as juice from citrus fruit contacting the skin.
  • The most common photosensitising medicines are tetracyclines, sulphonamides, fluoroquinolones, chlorpromazine, diuretics as well as piroxicam and other anti-inflammatory drugs. In addition, several other medicines are also capable of causing photosensitivity Photodermatitis.

Treatment

Prognosis

Late effects of ultraviolet radiation on the skin

  • The best prevention is to avoid the sun during the midday hours, use protective clothing, also when swimming, and gradually increase the skin's tolerance of the sun.
  • Protection against the sun should be provided with clothing, a wide brimmed hat, sun glasses and sunscreeens with a sufficiently high sun protection factor (SPF 30-50).

Orthostatic purpura (stasis purpura)

In hot climate and when standing for prolonged times, the legs of even a health individual may swell. As venous pressure increases, erythrocyte extravasation into the skin may occur and orthostatic purpura develop in lower extremities.

Miliaria

  • Miliaria is also known as sweat rash and is caused by a blockage of the sweat ducts.
  • Approximately one third of persons exposed to a hot climate are likely to develop miliaria. The condition is more common in young children than in adults.
  • May develop after only a few days' stay in a hot climate.
  • The presentation of miliaria depends on the level at which the blockage occurs.
    • The most superficial form is miliaria crystallina where the vesicles, caused by sweat retention, occur under the stratum corneum (picture 5).
    • In the deeper miliaria rubra the sweat ducts in the epidermis become obstructed and rupture.
    • In the deepest form the rupture occurs at the dermal-epidermal junction.
  • The result is the appearance of small, reddish, sharp pointed spots that cause a prickling sensation on the skin, particularly on the upper body and flexural areas.
  • Treatment consists of the avoidance of sweating and the management of possible secondary bacterial infection.
  • Even a short stay in an air-conditioned environment will bring relief.

Insect bites and stings

  • A variety of biting and stinging insects are encountered in tropical and subtropical countries. Mosquitoes in the genus Culex which breed in the sewers are frequent the Mediterranean countries.
  • Certain blood sucking insects can also act as vectors for infectious diseases.
  • See also the article Insect bites and stings Insect Stings and Bites.

Clinical presentation

  • Irritation or immediate allergy will initially cause a wheal on the bite site, which is followed by a persisting papule as a consequence of delayed allergy, which often becomes infected due to scratching.
  • The delayed reaction to an insect bite may take several days to develop and last for several weeks.
  • Bites by cat and dog ticks, or bird mites, appear as clusters of a few itchy and erythematous marks on the skin areas covered by clothing.
  • Bed bugs (Cimex lectularius) are active at night. Bed bugs bite exposed skin areas, which may cause reddening and swelling with occasional vesicle formation in the surrounding area.

Treatment

  • A bite or sting site can be treated with a tripelennamine containing insect stick or with corticosteroid creams and liniments.
  • Itching can be managed with antihistamines.
  • Insect bites may cause secondary bacterial infections which necessitate antimicrobials.

Prevention

  • The prevention of insect bites mainly consists of the use of protective clothing, insect repellents applied to the skin and bed nets at night time (mosquito nets).
  • Persons known to react strongly to insects bites may use prophylactic antihistamines.

Toxic effects of marine animals

  • Bites and stings by tropical marine animals may also contain toxins, and the toxic effects may also become manifest without a visible skin puncture. A break in the skin obtained in warm water may also easily become infected.
  • These bites and stings are usually very painful; general symptoms should be anticipated depending on the toxicity of the animal in question.
  • Marine animals with a sting or bite that has potentially fatal effects include: some jellyfish species, such as box jellyfish and Irukandji jellyfish, Portuguese man-o-war, blue ringed octopus, some cone shell species as well as some fish species, such as stonefish and scorpionfish.

Prevention

  • A diver, snorkeler or swimmer must never touch anything living!
  • Tetanus prophylaxis before travel

Treatment

  • First aid consists of cleaning the wound and the removal of any foreign bodies if possible (note, the rescuer must also protect himself/herself against poisonous stings and tentacles)
  • Neutralising possible toxins: mild vinegar solutions are often used. Some of the toxins are heat-labile, in which case immersion in warm water (45°C) for more than 30 minutes will relieve pain in particular.
  • Risk of infection: the poisons cause tissue destruction and particularly gram-negative rods are abundant in tropical sea waters. The treatment of an infected wound requires a very broad-spectrum antimicrobial, e.g. clindamycin + fluoroquinolone (a first-generation cephalosporin is usually not sufficient).
  • The culture request form should include information of the origin of the wound.

Fungal diseases

  • Fungal infections, particularly tinea pedis (athlete's foot), are the most common skin diseases in travellers.
  • Deep fungal infections Deep Endemic Mycoses are rare in travellers.
  • The diagnosis and treatment of fungal diseases of the skin: see Dermatomycoses

Tinea pedis

  • The traveller has usually already contracted the infection in his/her home country. Increased sweating in the warm climate will activate the infection.

Candida albicans yeast

  • Causes maceration and weeping in the flexural areas as well as between the toes and sometimes also between the fingers.
  • Obese individuals as well as those with diabetes are particularly susceptible to yeast infections.

Pityriasis versicolor

  • See Pityriasis Versicolor.
  • A superficial fungal infection caused by the Malassezia yeast
  • As the rest of the skin becomes tanned the areas of skin covered by fungal scales will remain pale. The patches may resemble vitiligo.
  • The Malassezia yeast may also cause highly pruritic superficial folliculitis which mainly affects the upper trunk area.

Sporotrichosis

  • Subcutaneous mycosis, encountered in warm and tropical climates.
  • The causative agent Sporotrichum schenckii is present in soil and mossy trees. An infection is acquired through a puncture in the skin.
  • The incubation period varies from a few weeks to six months.
  • A small ulcerating lump develops under the skin at the point of entry. Similar lumps will gradually spread proximally along the route of the lymph vessels.

Ring worm (tinea) and dermatophytosis

  • Tinea of the trunk and limbs (ring worm) and dermatophytosis caused by fungi of the Trichophyton and Microsporon genera (bald scaly patches and suppurating lesions on the scalp) are very common in the inhabitants of the tropics and subtropics.
  • Also occurs in the Mediterranean countries.
  • A traveller may be infected by wild dogs or cats.

Prevention of fungal infections

  • Proper treatment of the skin of the feet before travel
  • Avoidance of uncomfortable footwear as well as skin excoriation and fissures
  • Use of footwear, also at swimming areas
  • Have fungal powder or cream available for a flare up

Bacterial diseases

Pyodermias

  • Common in warm climates
  • The causative agent is usually Staphylococcus aureus or beta-haemolytic streptococci or a combination of these.
  • The pus formation may present as
    • an impetiginous lesion on healthy skin
    • secondary infection on bites, insect stings, skin excoriation, tinea pedis or scabies
  • Diagnosis and treatment: see Impetigo

Folliculitis

  • See Skin Abscess and Folliculitis.
  • May be superficial and limited to the follicular orifice or deep extending down to the follicular root, in which case an abscess may develop.
  • The use of thick creams and oils (e.g. suntan lotions) may cause acne-like folliculitis.

Erysipelas

  • See Erysipelas.
  • Pyogenic bacteria, beta-haemolytic streptococci in particular, may cause deep skin and soft tissue infections.
  • The portal of entry for infection is often skin excoriation or a fissure on the foot.
  • Symptoms include well-demarcated erythema, skin oedema, heat and pain.
  • The onset of erysipelas is usually abrupt, and it is associated with high fever.
  • Erysipelas is a serious septic infection, and parenteral antimicrobials are usually initially indicated.

Mycobacterial infections

Atypical mycobacteria

  • These are globally occurring environmental bacteria, which cause, for example, skin and soft tissue infections.
  • An infection is associated with a skin or mucous membrane puncturing wound or with contamination of a wound with water or soil containing mycobacteria.
  • The symptom is a localised, reddish and painless lump.
  • The most common type is hand infection caused by swimming pool or aquarium water, known as swimming pool granuloma, which is caused by the Mycobacterium marinum bacteria (picture 6).
  • Mycobacterium ulcerans, M. marinum and also M. tuberculosis may be the causative agents of persisting ulcerations in individuals who have resided in tropical and subtropical countries.
  • Diagnosis is based on histology of a skin biopsy, mycobacterial culture and the detection of the mycobacterial genome from a tissue sample with the PCR method.
  • The verification of diagnosis and treatment are the responsibility of a specialist.
  • Treatment consists of a surgical resection or a long course of antimicrobials.

Leprosy

  • See Bacterial Diseases in Warm Climates.
  • The causative agent is Mycobacterium leprae. The target organs are the skin and peripheral nerves.
  • Transmission usually requires prolonged close contact with a disease carrier. The incubation period is several years.
  • Leprosy may be associated with a multitude of chronic skin changes, e.g. patches where the skin is lighter than elsewhere and has reduced sensation, or thickened nodular skin throughout the body.
  • Leprosy is rare in travellers.
  • The verification of diagnosis and treatment are the responsibility of a specialist.

Skin changes caused by animal parasites

Rashes caused by worms

  • Pinworms (threadworms) Pinworm (Enterobiasis) cause pruritus in the anal orifice and may occasionally also trigger urticaria.
  • The migratory phase of the nematode larvae in the human body may result in urticaria.
  • Hookworm Hookworm Disease (Ancylostoma duodenale and Necator americanus) and Strongyloides stercoralis penetrate human skin when walking barefoot. This may lead to pruritic skin irritation that lasts for 1-2 weeks.
  • Strongyloidiasis Strongyloidiasis may be accompanied by anal rash and larva currens (”racing larvae”): usually linear urticaria, which appears and disappears abruptly while changing its site of appearance.
  • Schistosomiasis (bilharziasis) Schistosomiasis (Bilharziasis) may be associated a few hours after infection with pruritic cercarial dermatitis with red papules; the rash resolves within 7-10 days. About 4-6 weeks after infection the patient may develop acute schistosomiasis, which is often manifested as fever, generalised symptoms and urticaria.

Cutaneous larva migrans (creeping eruption)

  • Hookworm larvae originating from animal hosts (cats and dogs) may penetrate human skin, which is followed by subsequent migration of the larvae in the subcutaneous tissues (larva migrans).
  • Infection is common in warm climate zones, particularly in children.

Clinical presentation

  • The primary lesion is usually a small erythematous papule on the foot from where the larvae start migrating either immediately or not until after several weeks.
  • The route of the larvae is marked by small vesicles on the skin, and raised, serpiginous tracts become visible and can advance several centimetres per day (picture 7).
  • Pruritus may be intense.
  • Infection may sometimes be accompanied by eosinophilia.
  • The larvae will die within a few weeks or months and the symptoms will resolve spontaneously.

Diagnosis

  • The diagnosis is clinical and based on the classic presentation.
  • It is important to differentiate cutaneous larva migrans from the similar ”larva currens” -skin manifestation seen in strongyloidiasis Strongyloidiasis, which, however, advances faster and disappears within a few hours.

Treatment

  • The first line treatment in cutaneous larva migrans is oral ivermectin (100-200 µg/kg × 1), treatment period 1-2 days), alternatively albendazole (400 mg twice daily, treatment period 3 days).
  • Surgical excision is not recommended.
  • An infectious disease physician or specialist dermatologist can be consulted as regards the treatment choices.

Cutaneous leishmaniasis

  • See Leishmaniases.
  • A protozoal disease; spread by sandflies
  • The incubation period usually varies from 2 weeks to 6 months, but may be as long as 2 years.
  • First, an asymptomatic papule develops at the site of the bite. This expands to an ulcer with a typically raised margin (picture 8). The bottom of the ulcer may be moist or covered with scaly crust.
  • Diagnosis can be made from a biopsy or tissue scraping sample obtained from the ulcer margin or nodule; the diagnostic techniques used are Leishman stain and PCR assay.
  • Depending on the lesions and the Leishmania species, the treatment chosen is either topical or pharmaceutical. In New World leishmaniasis, parenteral drug therapy is usually indicated since the infection may lead to mucocutaneous leishmaniasis.
  • If cutaneous leishmaniasis is suspected, a specialist dermatologist or infectious disease physician should be consulted.

Scabies, body lice, pubic lice, head lice

  • Prevalent globally, and therefore possible in returning travellers.
  • Symptoms include pruritus and infection secondary to scratching.
  • See also Scabies Head Lice and Pubic Lice.

Tungiasis

  • Tungiasis is a painful skin lesion caused by a sand flea (Tunga penetrans), most commonly found between the toes or on the periungal region of the toes (picture 9).
  • Walking barefoot on a tropical sandy beach will allow a sand flea to attack the skin of a human foot.
  • The flea lays its eggs inside a capsule, which will enlarge into an itchy pea-sized dark papule.
  • Diagnosis is clinical. The contents of the papule can be microscopically identified.
  • Treatment consists of the careful mechanical removal of the entire egg sac followed by cleansing of the skin.
  • In some cases, secondary bacterial infection may develop.

Myiasis

  • Cutaneous myiasis is widespread in tropical and subtropical regions.
  • The infection usually follows a fly laying its eggs in damp clothing, from where larvae penetrate the skin. The fly may also lay its eggs in an open wound (picture 10).
  • The developing fly larvae feed on the host's tissues and body fluids.
  • A papule, which resembles an abscess, develops around the larva that resides under the skin. Each lesion has a visible central punctum, and the movement of the larva may be noticed by the patient. When mature the larva crawls out.
  • In cutaneous myiasis the larvae do not migrate elsewhere in the body, and the infection is not associated with complications. In some cases, secondary bacterial infection may develop.
  • Treatment usually consists of a simple removal of the entire larva through the central punctum, for example by squeezing. Petroleum jelly or other occlusive material may be applied over the central punctum to coax the larva to emerge, and thus aid its removal.
  • Prevention consists of ironing all clothing, including underwear.

Chemical burns by insects and larvae

  • In the southern parts of North America and South America about twenty larvae species are encountered which may cause severe skin irritation.
  • Nairobi flies
    • Approximately 1 cm long, these black and red insects occur in masses in East Africa after the first rains.
    • They do not bite but if crushed against the skin they release a toxin, which causes a burning and erythematous lesion 12-24 hours later, often with blister formation and later on crusting.

Febrile systemic infections accompanied by rash

  • Many febrile systemic infections may be accompanied by skin symptoms (table T1).
  • See also Table Exanthems associated with febrile infections in tourists Exanthem (Eruptive Skin Rash).
  • Petechiae, eccymoses and haemorrhages may be signs of a meningococcal disease Meningitis in Adults or rare haemorrhagic fevers capable of human to human transmission (Crimean-Congo haemorrhagic fever, Ebola haemorrhagic fever, Lassa fever, Marburg haemorrhagic fever) Viral Diseases in Warm Climates, a suspicion of which may require stricter than routine procedures in the handling of both the patient and clinical specimens. Petechiae and eccymoses may also occur, among other conditions, in dengue Viral Diseases in Warm Climates, spotted fevers Bacterial Diseases in Warm Climates and leptospirosis Bacterial Diseases in Warm Climates.
  • Maculopapular rash may indicate measles Measles, Mumps and Rubella (Mmr), an acute HIV infection HIV Infection, secondary syphilis Syphilis, leptospirosis or Zika virus infection.
  • Dengue and chikungunya fever Viral Diseases in Warm Climates are usually accompanied by a faint skin erythema that resembles measles; it may be difficult to detect, but the rash may also be maculopapular in appearance. Dengue is characterised by light coloured skin areas and patches free of rash and, in severe cases, by haemorrhages (picture 11).
  • Typhoid fever may have faint pink patches on the skin (”rose spots”).
  • An eschar or tache noire (a dark scab) is a typical finding in tick-borne spotted fevers, i.e. rickettsioses (picture 12), anthrax and Crimean-Congo haemorrhagic fever.
  • Tularaemia Tularaemia is characterised by a festering skin ulcer.

Skin manifestations of some infections

Appearance of skin manifestationPossible diagnosis
Maculopapular rash
Dengue, other arbovirus infections
Acute HIV infection
Syphilis
Measles
Mononucleosis
Cytomegalovirus infection
Rickettsiosis, i.e. spotted fever
Leptospirosis
Zika virus infection
Haemorrhagic fevers
Erythema chronicum migrans
Reddish nodule or swelling (lymphocytoma)
Borreliosis, i.e. Lyme disease
Rose spots
Typhoid fever
Pustules
Staphylococcal infection
Generalised gonococcal infection
Petechiae, eccymoses, haemorrhages
Meningococcal disease
Dengue
Rickettsiosis, i.e. spotted fever
Leptospirosis
Yellow fever
Haemorrhagic fevers
Dark scabs (eschar, tache noire)
Rickettsiosis, i.e. spotted fever
Anthrax
Crimean-Congo haemorrhagic fever
Ulcer
Tularaemia
Cutaneous diphtheria
Syphilis
Cutaneous leishmaniasis
Urticaria
Tissue invasion phase in helminthic infections
Acute schistosomiasis