Travel-acquired / worldwide cutaneous infections

This chapter provides a brief overview of worldwide cutaneous infections that may be seen as a result of travel and immigration, or, presenting in an individuals native country.

This chapter is set out as follows:

The conditions discussed in this chapter are those seen most frequently and/or of particular importance. The list of conditions includes:

• Common infections
• Myiasis 
• Those associated with fever:
  • ​Dengue fever
  • Chikungunya
  • South African tick typhus (or African tick-bite fever)
  • Rocky Mountain spotted fever (RMSF)
  • Acute schistosomiasis (Bilharzia) - Katayama fever
  • Malaria
• Lyme disease 
• Leishmaniasis
• Cutaneous larva migrans 
• Leprosy
• Mycobacterial infections other than leprosy are discussed in the related chapter. They are one of the great mimickers and have many cutaneous presentations including plaques, nodules, ulcers, papules and pustules, and non-tender abscesses
• Sexually transmitted disease:
  • Chancroid
  • Lymphogranuloma venereum
  • Granuloma inguinale (syn. Donovanosis)

​This chapter provides a brief introduction into just some of the infections that can be acquired abroad. For further reading, including on treatment, please refer to the section at the bottom of this chapter. 

Common infections

• An infection acquired abroad is most likely to be a common bacteria, virus or fungus 
• Both staphylococcus aureus and streptococcus pyogenes may complicate excoriated insect bites or any trauma to the skin, causing cellulitis / erysipelas. Impetigo is also a common manifestation
• Tinea corporis and pityriasis versicolor are commonly found in the tropics

Myiasis 

• Myiasis presents as a painful lesion similar to a boil
• It is caused by an infestation of the skin by developing larvae (maggots) of a variety of fly species (myia is Greek for fly) within the arthropod order Diptera. Worldwide, the most common flies that cause human infestation are Dermatobia hominis (human botfly) and Cordylobia anthropophaga (tumbu fly)
• Its incidence is higher in the tropics and subtropics of Africa and the Americas, however, it can also be found in temperate zones over the summer months 
• Myiasis presents as a papule, which enlarges into a nodule, which may be tender, purulent and crusted. There is a central punctum that allows the larva to breathe, and sometimes the tip of the larva may protrude through the punctum or bubbles produced by its respiration may be seen. Occasionally movement of the larva may be noticed by the patient
• Occasionally cutaneous myiasis may migrate, when it can have a similar clinical appearance to cutaneous larva migrans
• Extraction of the fly larva can be difficult, especially of the bot fly; extraction may be facilitated by first asphyxiating the larvae, usually with an occlusive dressing or covering (such as a bottle cap filled with petroleum jelly) for several hours, and then squeezing the larva out

Rash with fever 

Most such cases will be common viral infections, however, it is important to consider the following:

• Dengue fever

• Dengue is a viral infection transmitted by primarily female mosquitoes mainly of the species Aedes aegypti and, to a lesser extent, Aedes albopictus 
• Dengue is found in tropical and sub-tropical climates worldwide, mostly in urban and semi-urban areas.The global incidence of dengue has grown dramatically in recent decades and about half of the world's population is now at risk. Severe dengue is a leading cause of serious illness and death among children in some Asian and Latin American countries
• The characteristic clinical features are an abrupt onset of high fever, frontal headache (often accompanied by retro-orbital pain), myalgia, and a faint macular rash (containing islands of pallor) that becomes evident on the second to fourth day of illness. A petechial rash may be found in classical dengue, as well as severe dengue (such as dengue haemorrhagic fever)
• Antigen and antibody detection tests, as well as PCR assays are available to diagnose dengue; detecting IgM in the appropriate clinical scenario would support the diagnosis
• There is no specific treatment for dengue / severe dengue, but early detection and access to supportive medical care lowers fatality rates below 1%
• Other haemorrhagic fevers - particularly during epidemics it is important to consider other diagnoses such Ebola haemorrhagic fever and Lassa fever, which are found most frequently in West Africa

• Chikungunya

• ​Is a virus transmitted by the same Aedes mosquito that transmits dengue fever
• It has recently caused major outbreaks of illness in southeast Africa, South Asia, the Americas, and the Caribbean
• Chikungunya fever is similar to dengue clinically, including the rash, although haemorrhage, shock, and death are not typical of chikungunya
• A major distinguishing feature is that arthritis or arthralgia is common with chikungunya (and may persist for months), whereas in dengue, myalgia is the major clinical feature
• Similar to dengue, serologic tests are available. Treatment of the arthritis is with NSAIDs

• South African tick typhus, or African tick-bite fever (Rickettsia africae)

• ​This is the most frequent cause of fever and rash in southern Africa. It is transmitted by ticks
• The disease is characterised by fever and a papular or vesicular rash associated with localised lymphadenopathy and the presence of an eschar (a mildly painful 1-2 cm black necrotic lesion with an erythematous margin). Satellite lesions may be present
• Diagnosis is usually through clinical recognition and is confirmed by serologic testing. Treatment is with doxycycline

• Rocky Mountain spotted fever (RMSF)

• Although uncommon in travellers, is an important cause of fever and rash because of its potential severity and the need for early treatment
• This tick-borne infection is found in the United States, Mexico, and parts of Central and South America
• Most patients with RMSF develop a rash between the third and fifth days of illness. The typical rash of RMSF begins on the ankles and wrists and spreads both centrally and to the palms and soles. The rash commonly begins as a maculopapular eruption and then becomes petechial, although in some patients it begins with petechiae
• Doxycycline is the treatment of choice

• Acute schistosomiasis (Bilharzia) - Katayama fever

• Patients present usually 4-8 weeks after exposure to Schistosomiasis japonicum or Schistosomiasis mansoni, which are found in tropical subtropical and tropical regions worldwide 
• Wading and swimming in fresh water causes schistosomal trematodes to enter the body
• The distinguishing features from malaria include generalised urticaria, pruritic rash at the site of cercarial penetration (often the legs), eosinophilia, and lymphadenopathy

• ​Malaria

• ​Malaria is not commonly associated with a rash, although a number of cutaneous features such as urticaria have been reported
• The classic paroxysm of malaria is that of a period of shivering and chills, which lasts for approximately 1-2 hours and is followed by a high fever. However, many patients, particularly early in infection, do not present the classic paroxysm but may have several small fever spikes a day

• Other causes 

  • The category of fever with rash is large, and providers caring for ill travellers should also consider the following diagnoses: enteroviruses, such as echovirus and coxsackievirus; HIV and other sexually transmitted disease (see later in this chapter); hepatitis B virus; measles; Epstein-Barr virus; cytomegalovirus; typhus and leptospirosis

Lyme disease

• Lyme disease is an infection caused by the spirochaete Borrelia burgdorferi (B. burgdorferi), which is transmitted to humans by ticks
• It is common in parts of the United States (particularly in Massachusetts) and Europe (especially in Scandinavia and central Europe), and can be found in many areas of the world
• Affected patients usually live close to, or have visited, woodland areas where the ticks can be found along with their predominant hosts
• Patients most commonly present with spreading erythema that has a well-demarcated edge. The eruption is usually round or oval, but can be triangular or linear. Often, a central punctum is evident at the bite site
• For more information refer to the related chapter Lyme disease

Leishmaniasis

• Leishmaniasis is a parasitic disease spread by the bite of infected sandflies
• It is found in 88 countries with Latin America, the Mediterranean, the Middle East, Asia, and parts of Africa being the main areas of risk. Brazil, Afghanistan, Iran and Sudan have the highest prevalence
• Leishmaniasis is broadly classified as cutaneous or visceral, although the latter may cause cutaneous disease. It can also be divided into Old World (Asia and Africa) and New World (Central and South America)
• The incubation period varies from days to over a year
• While the cutaneous features can vary depending on the species, there is much overlap:
  • Lesions normally affect exposed areas of skin, especially the face and extremities
  • A red-brown nodule or plaque, or sometimes multiple papules 
  • Varying amounts of surface crust, with an underlying ulcer. The crust can be adherent or come away 
  • Papules may arise in the surrounding lymphatics, a process referred to as sporotrichoid spread
  • Lesion heal with scarring
  • Some species of Leishmaniasis can cause widespread lesions, such lesions tend to be nodules, which do not ulcerate 
• Mucocutaneous lesions
  • Papules, nodules and ulcers develop around the mucous membranes of the nose and mouth, and sometimes on the surrounding skin
  • Untreated the entire nasal mucosa and palates become deformed with ulceration and erosion of the nasal septum, lips and palate

Cutaneous larva migrans

• Cutaneous larva migrans is a parasitic skin infection caused by hookworm larvae that usually infest cats, dogs and other animals. Humans can be infected with the larvae by walking barefoot on sandy beaches or other surfaces that have been contaminated with animal faeces
• The condition is common in all warm climates 
• The most commonly affected sites include the feet, knees, buttocks, and hands
• Once the larvae have penetrated they can lay dormant for several weeks or months, which can lead to a mild irritant cutaneous reaction. Once they start to move the characteristic clinical features become apparent:
  • The larvae create 2-3 mm wide, snake-like tracks
  • The tracks are slightly raised, flesh-coloured or pink and cause intense itching
  • Tracks advance slowly, and if many larvae are involved a disorganised series of loops and tortuous tracks may form
• Cutaneous larva migrans is self-limiting with most larvae dying off within several weeks, however, some persist for many months. If treatment is required the first-line treatment is a one off-dose of ivermectin, alternatively topical thiabendazole can be used
• A similar lesion that may be more urticarial and that rapidly progresses is that of larva currens (running larva), caused by cutaneous migration of the filariform larvae of Strongyloides stercoralis

Mycobacterium leprae

• Leprosy is a chronic granulomatous condition cause by Mycobacterium leprae. It primarily affecting the skin and peripheral nervous system
• There are several forms of leprosy, the emergence of which depends on several factors including the host immunity and extent of spread. Infections range from the mildest indeterminate form, through tuberculoid leprosy to the most severe lepromatous type, with a spectrum inbetween. More severe forms arise because of a less effective immune response to the infection
• Leprosy is most common in warm, wet areas in the tropics and subtropics. Worldwide prevalence is approximately four million, with 60% of cases found in India, and many of the rest in Brazil, Indonesia, Myanmar, Madagascar and Nepal
• Leprosy presents most often during two different periods of life, between the ages of 10-14 and in those aged 35-44 years. It is rarely seen in infants
• Infection probably occurs though inhalation onto the nasal turbinates from where it disseminates via the blood to the skin and peripheral nerves. The source of infection also probably comes from the nose, arising from the nasal discharge of patients with lepromatous leprosy. In patients with the tuberculoid forms of leprosy, the infection remains within the skin and nerves, and such patients are probably never infectious 
• Once infected with the mycobacteria the average incubation period is 2-5 years, but can be much longer
• The morphology of leprosy varies from a red or hypopigmented patch or plaque, to multiple papules, plaques or nodules. There can be associated scaling. The precise features depend on the type of leprosy:

• Tuberculoid leprosy
• Patients have a strong cell-medicated response, which keeps the lesions localised, however, the strong inflammatory response results in more rapid nerve damage
• Lesions are one to several, presenting as hypopigmented plaques with a well-defined coppery-red edge
• There is early loss of sensation and hair, and anhidrosis
• Regional nerves can be very thickened
• There is no mucosal involvement

• Lepromatous leprosy
• A poor cell-mediated response enables bacillary multiplication with much more widespread disease. However, the reduced inflammatory response equates to a slower rate of nerve damage
• It presents with hundreds of macules, which may be erythematous or mildly hypopigmented, having indistinct borders. Lesions may become confluent
• Diffuse papules and nodules
• There can be symmetrical thickening of the skin over the forehead (leonine facies), with loss of eyebrows and eyelashes. There can also be thickening of the skin of the lower legs and feet, which can be scaly, and ulcers may develop
• The fingers may become shortened, and the nails brittle
• Neurological involvement:
  • Loss of sensation of the cutaneous lesions, and anhidrosis, occur much later
  • The nerves are less thickened
  • There is numbness of the dorsum of the hands and feet, with spreads up the limbs, and which then becomes more diffuse
  • The degree of motor involvement is less than the sensory change
    
• Other features seen in lepromatous leprosy include oral lesions sometimes with loss of the upper incisors, the nose may become misshapen or collapses, and blindness

• Borderline leprosy
• Inbetween tuberculoid and lepromatous leprosy are a spectrum of patients that are referred to as having borderline leprosy
• Patients have a range of clinical features, which are partly dependent on how close they are to the tuberculoid or lepromatous end of the spectrum. Those in the middle of the spectrum can present with irregularly shaped plaques
• Borderline leprosy is also associated with acute inflammatory episodes of both cutaneous lesions and the peripheral nerves 
• Other skin reactions include an erythema nodosum-like pattern

• The diagnosis is based on clinical features, histopathological examination of incisional biopsies taken down to subcutaneous fat that reveal granulomas and nerve involvement, and the use of Ziehl–Neelsen stain to look for acid fast bacilli (AFB). However, in some cases of early 'indeterminate' leprosy, there may be few clues to the diagnosis, and in tuberculoid leprosy AFB will be undetectable

• Prognosis - patients with indeterminate leprosy, a very early form of leprosy, may either be cured or progress to one of the other forms of leprosy depending on their immune status. Within each type of leprosy, a patient may remain in that stage, improve to a less debilitating form or worsen to a more debilitating form depending on their immune state. Although it is rare for tuberculoid leprosy to evolve into lepromatous leprosy, and lepromatous leprosy never reverts to a less severe form

Sexually transmitted disease (STD)

• General
• All of the common STD should be considered such as chlamydia, gonorrhoea, and trichomoniasis  
• Secondary syphilis presents with non-itchy, symmetrical, coppery-red, rounded-oval macules, which can be widely distributed. The palms and soles are commonly involved sites, and on the back lesions follow the lines of cleavage. Cutaneous features can be very subtle in 25% of patients
• HIV - many dermatological conditions have been associated including seroconversion rashes, moderate-severe cases of inflammatory dermatoses (eg psoriasis), mycobacterial infection, and opportunistic skin infections

• In tropical and subtropical regions the following should also be considered:

• Chancroid

• Is a sexually transmitted infection caused by the Gram negative bacterium Haemophilus ducreyi
• Was endemic worldwide until the 20th century, but is now most common in the Caribbean, Africa, Asia (except Thailand), and Latin America
• Lesions typically occur on the prepuce and frenulum in men and on the vulva, cervix, and perianal area in women
• Presents with a tender erythematous papule, which quickly progresses to a pustular stage
• Pustules often rupture after a further 2–3 days to form painful shallow ulcers with granulomatous bases and purulent exudates. The ulcer edge is typically ragged and undermined
• Painful, tender, inguinal lymphadenopathy typically occurs in up to 50% of cases and the lymph nodes may coalesce into buboes. The lymphadenopathy is usually unilateral

• Lymphogranuloma venerum (LGV)

• Is a STD caused by Chlamydia trachomatis
• Is endemic in certain areas of Africa, Southeast Asia, India, the Caribbean, and South America
• Has three stages
• Primary LGV is characterised by a self-limiting painless genital papule or ulcer
• Secondary LGV follows 2-6 weeks later and is characterised by painful inguinal and/or femoral lymphadenopathy, which may be less noticeable in women. The lymph nodes coalesce into buboes and may rupture. At this stage patients can have constitutional upset and systemic involvement 
• Tertiary LGV develops if the condition goes untreated, and can result in chronic inflammation and ulceration, proctocolitis, and genital elephantiasis

•  Granuloma inguinale (syn. Donovanosis)

  • ​Granuloma inguinale is a chronic bacterial infection that frequently is associated with other STD 
  • It is common in the tropics and subtropics and endemic in Western New Guinea, the Caribbean, Southern India, South Africa, Southeast Asia, Australia, and Brazil
  • The most common presentation is the ulcerovegetative form, which consists of large, red, usually painless, expanding, suppurative ulcers that have a raised edge and bleed easily
  • Other presentations include a nodule or hypertrophic / verrucous type
  • Elephantiasis-like oedema of the external genitalia is a frequent complication and is found most often in females in the later stages of infection

• Centres for Disease Control and Prevention (CDC)
• ​The Disease directory at the Centre for Disease Control and Prevention
• The Destination directory (on the linked page scroll down for the list) at the Centre for Disease Control and Prevention
• Parasitic infections at the Centre for Disease Control and Prevention

• The World Health Organization

• A Practical Approach to Common Skin Problems in Returning Travellers (article)