Skin Problems

CHAPTER 25 Skin Problems


Health problems in immigrants from developed to developing countries are very much a reflection of the endemicity of infectious diseases in the country of origin, the living conditions and socioeconomic status of the immigrant, ethnic differences concerning noninfectious diseases, and the time elapsed between departure from the country of origin and arrival in the country of destination. This chapter will cover only those skin diseases that are imported into developed countries from the developing world. A number of the conditions mentioned in this chapter are more fully covered in other chapters of this book and therefore will not be covered in detail. This chapter is not intended to be a comprehensive review of dermatological problems in immigrants, but rather an approach to the diagnosis of skin lesions based on their morphology, anatomical location, and associated symptoms.

There is a remarkable paucity in the medical literature concerning skin problems in immigrants from developing countries compared with those born in industrialized nations. One of the few reviews of immigrant dermatological problems was carried out in the late 1980s by five European hospital-based dermatology clinics, one each in the Netherlands and Germany, and three in the UK.1 In the Dutch clinic, the top diagnoses among im-migrants, mostly from Surinam, Turkey, Indonesia, Morocco, and the Caribbean, were contact dermatitis, alopecia, dermatophytosis, psoriaisis, herpes simplex, vitiligo and pityriasis versicolor. In hospitalized patients in Germany, made up mostly of Turks and Yugoslavs, idiopathic urticaria and sexually transmitted diseases (STDs) were the primary diagnoses. In a South London clinic, made up mostly of Afro-Caribbeans, the major disorders were those of pigmentation and hair. Curly hair was associated with folliculitis of the scalp, ingrown hairs of the beard, abscess formation, and keloid scarring. Traction alopecia was seen with changes in hair fashion. On the other hand, in the Asian population of South London, eczema, warts, dermatomycosis, and acne were the primary presenting diagnoses and were similar to the non-immigrant population. The middle-class Asian population reviewed in Leicester, England, were most likely to complain of pigmentary disorders (vitiligo, postinflammatory pigmentary alterations, and facial hyperpigmentation), idiopathic pruritus, and atopic eczema, compared with the non-Asian population. Among both Asian populations surveyed, there was considerable social stigma attached to vitiligo and other skin conditions that leave visible marks, especially those found in young women (Table 25.1).

Although dermatological problems among newly arrived immigrants are not well documented, several reviews have focused on skin problems in ethnic communities of which the majority would be immigrants.2 A survey of 75 589 patients seen over 2 years at the National Skin Centre in Singapore documented the spectrum of disease in its Asian population.3 The majority of its patients were Chinese with 5–10 % each of Indian, Malay, and others. The 11 most common diagnoses were: dermatitis (34.1%), acne (10.9%), viral infections (5.7%), fungal infections (5.4%), urticaria (4.7%), contact dermatitis (4.0%), psoriasis (3.3%,) bacterial infection (3.0%), alopecia (2.4%), nonvenomous insect bites (2.3%), and postinflammatory hyperpigmentation (1.9%).

Sanchez recently reported his findings on dermatological problems in 2000 Latinos in a large hospital based clinic.4 The top 10 diagnoses included: eczema/ contact dermatitis (20.1%), condyloma/warts (17.5%), acne (12.3%), tinea/onychomycosis (9.3%), pyoderma (8.8%), hyperpigmentation (7.5%), seborrheic dermatitis (7.2%), psoriaisis (5.5%), facial melasma (4.1%), and pruritus (2.3%).

Infectious skin problems in immigrants are often very much different from those found in returned travelers and immigrants returning home to visit friends and relatives (VFRs). In the latter, insect bites, secondarily infected bites, skin abscesses, cutaneous larva migrans, and myiasis are most common. On the other hand, immigrants, especially refugees, are more likely to present with more exotic diseases such as cutaneous leishmaniasis, scabies, and filariasis. A recent review of the geosentinel database showed that tourists made up 57% of the database, and accounted for the majority (47%) of the skin problems. On the other hand, 16% of the geosentinel database were made up of immigrants but only 8% of the dermatological problems were found in this group (p < 0.001) (Edie Lederman, personal communication [2006]).

In a recent study from France of 622 ill returned travelers, dermatological problems were the most frequent reason for consultation, making up 23.4% of all the medical conditions found in these travelers.5 Immigrants accounted for one-third of the 149 travelers with skin problems, only slightly less than tourists.


The approach to the diagnosis of skin problems in immigrants begins with a detailed epidemiological and exposure history. The history should begin with a review of the patient’s travel history, beginning with the country of origin, as well as any stops en route to the final destination. It is not unusual for an immigrant or refugee to have spent time in one or more countries, sometimes in refugee camps, before arriving in the destination country. This information is particularly important with respect to possible exposures to infectious diseases as well as in the determination of the incubation period of the skin problem. The history should also include information concerning the specific region within the country that has been visited, as well as that of the country of origin. Many infectious skin problems are confined to rural areas only or to specific regions within a country.

The type of activities or work in which immigrants were involved while in their country of origin or asylum affects the infectious diseases, vectors, and environmental hazards to which they might have been exposed. One has to assume that they are exposed to almost everything since they are less likely to remember or be aware of specific exposures. Unlike the history in returned travelers, who are often knowledgeable about their potential exposure during travel, immigrants will have been exposed to infections over many years, and therefore may be less certain about this history. It is important to take a detailed occupational history since, for example, farmers, mineworkers, and animal handlers will potentially have an entirely different set of infections than will urban workers. Similarly, immigrants who have been in transit through refugee camps in remote areas of developing countries will be exposed to the diseases of that region as well as to infections that might be transmitted from person to person within the refugee camps.

Immigrants are more likely than returned travelers to be knowledgeable about infectious diseases in the areas where they have lived in their country of origin. Although they may not know the medical terminology for a particular infection, they will often know about the symptoms, such as the swelling of the eye in the case of Loa loa or Chagas’ disease, limb enlargement in bancroftian filariasis, the skin ulcer of leishmaniasis, or of the deformities seen in leprosy. In addition, they will often be able to tell the healthcare provider whether they have come from an area where there are tsetse flies, ticks, or reduviid (Vinchuca, assassin) bugs. In the case of the latter, it will be important to know whether an individual has lived in a residence which was adobe-style or had a thatched roof.

The dietary history, with an emphasis on culturally diverse foods, is particularly important. For example, the eating of uncooked pork, raw fish, watercress, or shellfish may be an important clue to the diagnosis of tapeworm (or cysticercosis), gnathostomiasis, fascioliasis, or paragonimiasis, respectively.

Finally, it will be important to know the family history, both present and past, to assess whether the patient might have been in contact with family members with infectious diseases such as scabies, head lice, body lice, tuberculosis, or leprosy.

Laboratory Investigations (General Principles)

Laboratory investigations may be non-specific, such as a complete blood count, or specific, such as disease serology or biopsy and culture of a lesion. It is important to understand that alterations in the white blood count, such as eosinophilia, may or may not be related to the clinical problem under investigation (see Ch. 21). Not infrequently, immigrants from developing countries have eosinophilia due to a cryptic helminth infection; therefore, eosinophilia in the presence of skin lesion may be completely unrelated to the clinical problem. Along the same lines, serological tests for infectious diseases, particularly when the disease is chronic, cannot distinguish between an active infection and one that has been treated and cured. For example, a patient who has leishmania antibodies and a skin ulcer may not have active cutaneous leishmaniasis but rather evidence of a previous, silent infection.

The gold standard for the diagnosis of a cutaneous skin problem is the skin biopsy. The biopsy should be carried out at the most active portion of the lesion and include a portion of normal skin. In the case of leprosy, normal skin is not required and the biopsy should include subcutaneous fat in order that cutaneous nerves may be visualized. If there is a possibility that the cutaneous lesion has an infectious etiology, the biopsy should always be sent for bacterial, mycobacterial, and fungal cultures, and stains for these infections should be performed. In specific situations, special cultures, stains or polymerase chain reaction (PCR) for viruses or Leishmania may be required.

In leprosy, in addition to the skin biopsy, slit skin smears are often used to detect mycobacteria, while in onchocerciasis skin snips are used for the detection of microfilariae.

It would be impossible for one to cover all of the possible infectious skin disorders found in immigrants and refugees. Febrile illnesses associated with rash have been covered in the tabular approach to differential diagnosis. In this chapter, cutaneous infectious diseases that are most common among immigrants, or that are rare, but less likely to be recognized by practitioners have been selected for a more detailed discussion. Other diseases, including some found in other chapters, have been included in table form according to their clinical appearance (Table 25.2).

Table 25.2 Tropical dermatology quick reference: differential diagnosis

Papular Lesions


Although scabies has been a scourge of humans for thousands of years, it has enjoyed a resurgence recently because of the HIV epidemic and its association with a form of disease which is highly infectious due to the large numbers of mites present. Scabies is caused by the mite Sarcoptes scabei var. hominis, an ectoparasite requiring an appropriate host on which to feed. Symptoms of scabies usually begin 10–30 days after the onset of the infection, but may occur within 48 hours of a repeat infection because of host hypersensitivity.6,7

Human scabies is transmitted mainly by direct personal or sexual contact, and less often by contact with infested bedding or clothing. The gravid female mite burrows into the skin. Mature adults lay eggs at the rate of two or three per day, and a new cycle of replication will occur. At any given time, the average infected human has approximately 10–15 adult female mites. Scabies is characterized by severe pruritus. The characteristic primary lesion is the burrow. It appears as a white or gray linear, raised papule with a small vesicle at one end. These primary lesions are found in the web spaces of the fingers, on the flexor surfaces of the wrists and the elbows, on the penis, the scrotum, umbilicus, beltline and on the areola of the breasts in women. Secondary papules, pustules, vesicles, and excoriations may be present. The secondary lesions, often more numerous and more spread out than the burrows, likely represent an immune response to the infection. While scabies lesions are very uncommon on the head and neck area, infants not infrequently have involvement of the face and may have widespread, extensive lesions.

Norwegian or crusted scabies occurs in those patients who are immunocompromised, particularly among homeless individuals and those with AIDS. In this infection, the individual has severe cutaneous crusting due to hundreds to thousands of adult mites.8 In contrast to scabies in the immunocompetent host, papules and burrows may be limited or absent and pruritus may not occur. Crusted lesions may be found in the head and neck region and are found around the buttocks and perianal region.

Scabies should be one of the first diagnoses to be considered in any immigrant who presents with generalized pruritus. It is important to remember that one family member may have scabies while others may not be infected or symptomatic. The diagnosis of scabies can be confirmed by finding mite ova or excreta using a skin scraping with an oil-covered scalpel blade. Scrapings can then be placed on a slide for a microscopic examination. Because so few mites are present, multiple examinations are often necessary.

Treatment of scabies includes management of the pruritus, treatment of secondary bacterial infection, eradication of the scabies mite, and prevention of secondary transmission.9 Topical antiscabetic treatments include sulfur compounds, benzyl benzoate, crotamiton oil, lindane, malathion, permethrin, and ivermectin. Currently, the drugs of choice include 5% permethrin and ivermectin. The former should be applied from the neck down at bedtime and washed off in the morning and repeated in 1 week. All household members should be treated and all bedding and clothing of the symptomatic case should be washed in hot water. Ivermectin, in a single dose of 150–200 μg per kg, is a very safe avermectin derivative that is taken orally.10,11 It is the treatment of choice for Norwegian scabies and in the case of an institutional outbreak. It is a convenient oral medication, but may be costly when a large family requires treatment. The pruritus of scabies may take 6–8 weeks to resolve after successful treatment because of the hypersensitivity reaction to parasite antigen in the skin.

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Aug 11, 2016 | Posted by in INFECTIOUS DISEASE | Comments Off on Skin Problems

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