Medical and Cutaneous Disorders Associated With Homelessness

Alexander J. Stratigos, MD, Andreas D. Katsambas, MD

In This Article

Skin Diseases in the Homeless

Cutaneous disease is a frequent cause of morbidity in the homeless. Several skin conditions, both infectious and noninfectious, have been described in the homeless population including trauma, cellulitis, pyodermas, impetigo, gas gangrene, tinea infections, leg ulcers, stasis dermatitis, immersion foot, frostbite, erythromelalgia, pellagra, scurvy, scabies, pediculosis, seborrheic dermatitis, eczematous dermatitis, rosacea, and pruritus.[36,37,38,39] The incidence of skin disease is largely determined by a complex set of factors, namely geographic area, climate, living conditions, access to primary medical care, and coexistent medical conditions. Additional factors that are intrinsically related to homelessness, e.g., malnutrition, exposure to hazardous environments, and psychiatric illness, may have a negative impact on the extent and severity of skin disease. Many of the skin diseases of the homeless are easily diagnosed and treated, but because of the limited access of the homeless to health care resources and the high prevalence of mental illness and alcoholism in this population, homeless persons are likely to neglect skin care until their condition becomes disabling or even life-threatening.

Several studies[36,39] have reported an increased incidence of foot problems, primarily superficial fungal and bacterial infections. In a cohort of 142 homeless men staying overnight in a major Boston shelter over a period of 3 months, 38% had tinea pedis, 20.4% had pitted keratolysis of the feet, and 15.4% had toenail onychomycosis.[40] These diseases are usually related to poor foot hygiene, inadequate footwear, and excessive moisture. Overcrowding in shelters may also increase the risk of cutaneous infections due to exposure to potential pathogens. Tinea infections are quite common in the general population as well, but in homeless people they often represent a portal of entry for fungal and bacterial pathogens that, in the setting of compromised skin care, may lead to more serious or severe infections. Bacterial infections, such as cellulitis and pyodermas, are frequent causes of hospitalization among the homeless. In a survey of admissions to the inpatient dermatology service of a New York municipal hospital,[36] 46% of the admitted patients were street-living or shelter-based homeless and almost one half of them (48%) were diagnosed with cellulitis or other skin infections.

Immersion foot (trench foot) is another problem seen with increased frequency among the homeless population.[41] It results from cutaneous injury by water absorption in the stratum corneum of the skin and it is seen more often in street homeless due to improper footwear, prolonged exposure to moisture, and long periods of walking and standing. The syndrome of immersion foot can be exacerbated by peripheral neuropathy, peripheral vascular disease, and the use of tobacco or other vasoconstrictive drugs, e.g., cocaine. Infection or ischemic injury may complicate this condition, requiring antibiotics or surgical treatment.

Parasitic infestations of the skin are seen frequently in the homeless population, with scabies and pediculosis being the most prevalent. Recently, an increasing incidence of infection with Bartonella quintana, the etiologic agent of trench fever, has been observed in the homeless and is presumably transmitted through body lice.[42]B. quintana endocarditis and bacteremia have been reported in homeless patients living in downtown Seattle, Oregon, and Marseille, France.[37,43] In addition, prospective serologic studies have found antibodies to B. quintana in 25%, 30%, and 54% of the homeless population in Seattle, Marseille, and downtown Paris, respectively, compared with only 2% of the control group.[44,45] In the latter study, the serologic profile suggested a recent or evolving B. quintana infection in 25% of patients with positive serologies. Independent risk factors associated with a positive serology include the age of patients (adjusted relative risk, 2.9 for age >40 years) and the duration of homelessness (adjusted relative risk, 3.0 for ≥3 years of homelessness). An association between B. quintana infection and body lice infestation has been shown, although, in multivariate analysis, the number of previous episodes of body pediculosis was not a risk factor for a positive B. quintana serology. It is possible that the total duration of infestation is the main risk factor, as opposed to the number of new infestations by body pediculosis. The consequences of this high seroprevalence of B. quintana in the homeless population is yet undetermined in terms of its related morbidity and mortality. B. quintana has been recently identified as a significant cause of blood-culture negative endocarditis,[46] and, since heart disease is a major cause of death in homeless people, there could be a possible link between B. quintana infection and cardiac disease in this population. Aside from this hypothesis, current evidence suggests that prolonged homelessness is a major risk factor for B. quintana infection and that every homeless person with body lice infestation should be considered for serologic screening for B. quintana.

Common skin dermatoses, such as psoriasis, seborrheic dermatitis, and atopic dermatitis are also seen in the homeless population. Although their prevalence is not exactly known, it does not appear to differ from that of the general population.[40] It is possible that the severity and extent of these diseases is greater because of poor hygiene conditions, frequent exposure to exacerbating factors (cold, moisture), and difficulties in medical access.