Atopic dermatitis and HTLV-1 associated-myelopathy: associated or coincidental disorders?

Reports from Jamaica have indicated that some patients with infective dermatitis or atopic dermatitis (AD) are seropositive for antibodies to human T-lymphotropic virus type 1 (HTLV-1). We describe a 32-year-old Israeli woman with long-term AD and paresthesia in the distal parts of the extremities. Neurological examination revealed a positive Babinski's sign. HLA typing demonstrated that this patient has the common HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and infective dermatitis haplotype for DRBI* DQBI*. The presence of HTLV-1 was demonstrated with polymerase chain reaction; HTLV-1-antibodies were detected by the Western blot method and by inoculation of the patient's peripheral blood mononuclear cells into F344 rats. This study confirms the presence of HTLV-1 antibodies and proviral genome in a patient with AD which later evolved into HAM/TSP. We cannot yet conclude whether these two diseases are associated or coincidental disorders.(Au)

T cells and the skin

In addition to its role as a mechanical barrier, the skin plays an important role in temperature regulation, vitamin D synthesis and absorption of ultraviolet radiation. The importance of the skin as an immunological organ was not fully appreciated until the advent of immunosuppressive agents such as cyclosporin and tacrolimus, which have a predominant action against T lymphocytes and have been found to be effective in the management of common skin diseases such as atopic eczema and psoriasis. T lymphocytes are of fundamental importance to the immune system. Access from the vascular compartment into the skin is facilitated by adhesion molecules located on the endothelial of dermal blood vessels. Selective upregulation of adhesion molecules occurs in various inflammatory skin diseases and specific skin homing T lymphocytes preferentially enter the skin rather than other organs. T cell have recently been classified into Th1 and Th2 cells based on their cytokine profile. Th1 cells produce interleukin 2 (IL-2) and interferon gamma, important in macrophage activation and cytotoxity, and Th2 cells produce IL-4 and IL-5, important in B cell maturation and humoral immunity. Contact dermatitis and psoriasis are characterised by Th1 cells and atopic dermatitis by Th2 cells. The Th1/Th2 profile is also important in infectious diseases such as leprosy in which polarisation towards tuberculoid or lepromatous disease depends on a predominance of Th1 or Th2 cells, respectively. Future management of diseases affecting the skin is likely to depend on a greater understanding of the infiltrating T cell subsets and appropriate modulation of the Th1 and Th2 profile.(AU)

Is enough dermatology training given to primary health physicians?

Large numbers of patients with minor skin ailments are being referred by primary health physicians to skin clinics with little attempt at diagnosing and treating these cases. This study evaluated whether primary health physicians were exposed to enough dermatology in their training to diagnose and treat simple dermatoses. In this retrospective cross-sectional survey the diagnosis, treatment, source of referral of all patients seen between January and June 1997 in two health centres in East Trinidad, Sangre Grande (SG) and Arima (A), were reviewed. There werer 146 registered patients at Sangre Grande and 189 at Arima. The commonest skin disorder was eczema (SG 37 percent, A 38 percent). The ability to diagnose this condition was 25 percent in Arima and 7 percent in Sangre Grande. Atopic exzema was the commonest in childhood (A 16 percent, SG 13 percent). Fungal infections, which included tinea corpois (A 8 percent, SG 7 percent) and tinea capitis ( A 15 percent, SG 8 percent), were the next most common dermatoses seen. The diagnostic ability for tinea corpois was: A 13 percent SG 0 percent; but there was a higher diagnostic index for tinea capitis (A 52 percent, SG 50 percent). Psoriasis (A 21 percent, SG 7 percent), like tinea capitis, had a diagnosis index of 50 percent. The most common referring diagnosis was skin rash (43 percent, SG 45 percent) or fungal rash (A 38 percent, SG 36 percent). There were significant differences in gender (P <0.05) and ethnicity (P<0.001) in Arima. In conclusion, the commonest dermatoses seen in both centres, were the eczemas, fungal infections and psoriasis. Diagnostic ability was low for the eczemas and tinea corporis, the commonest skin disorders, but better for tinea capitis and psoriasis. Increase referrals fof common skin disorders leads to overcrowding, decreasing the time for the dermatologist to do procedures, to teach and to give earlier and more frequent appointments to needy patients. Cost of treatment of patients and to Government is lower when the diagnosis is made on the initial visit, and loss of school days for tinea capitis can be decreased by prompt and effective treatment.(AU)

Clinical, pathologic, and immunologic features of human T-lymphotropic virus type I- associated infective dermatitis in children

Objectives: To define the clinical and laboratory features associated with infective dermatitis (ID) and confirm its association with human T-lymphotropic virus type 1 (HTLV-I). Design: A case series of patients with ID were compared with patients with atopic dermatitis (AD) which is an important disease in the differential diagnosis of ID. Setting: Patients were recruited from dermatology and pediatric clinics at the University Hospital of the West Indies and the Bustamante Children's Hospital, Kingston, Jamaica. Main Outcome Measures: Clinical and laboratory features of patients with AD were compared with those of patients with ID. Patients: Consecutive patients older than 1« years diagnosed as having ID (n=50) and AD (n=35) were enrolled based on clinical findings. Results: The mean age of patients with ID and AD were 6.9 and 7.8 years, respectively. Histologically, both disease were predominantly chronic dermatitis... Conclusion: Infective dermatitis is a distinct clinical entity associated with HTLV-I, which plays a role in the pathogenesis and immune perturbations observed.(AU)

The prevalence of atopic dermatitis in black Caribbean children in London and Kingston, Jamaica

It has been suggested that black children of West Indian origin living in London have a higher prevalence of atopic dermatitis (AD) than their counterparts living in the Caribbean. (Williams HC et. al London-born black Caribbean children are at increased risk of atopic dermatitis. J Am Acad Dermatol 1995; 32: 212-7). To test this hypothesis, we undertook a colloborative study on the prevalence of atopic dermatitis in school children in Lambeth, London and Kingston, Jamaica. Questionnaires were sent to 2126 and 3957 parents of children aged 4 to 11 years attending seven primary schools in London and six schools in Kingston respectively. The questionnaires requested screening information on symptoms of AD and parentally nominated ethnic group of the child. Children whose parents responded affirmatively to the presence of an itchy rash or the presence of generally dry skin (N=562) were examined during two visits to the schools in London. In Kingston, all children whose parents responded and gave consent were examined (N=3027) by the same dermatologist. Cases of AD were defined using the UK Working Party's Diagnostic Criteria. The overall response rate in London and Kingston was 70.3 percent and 86.2 percent respectively. The overall prevalence of AD was 10.8 percent (162/1495) and 4.9 percent (166/3409) in London and Kingston respectively. The prevalence of AD in black children living in London was 18.9 percent (60/317) compared with 4.6 percent (94/2029). These results suggest that black Caribbean children in London are at an increased risk (odds ratio 4.81, 95 percent confidence interval 3.3 to 6.9, p<0.001) of developing atopic dermatitis when compared to their counterparts living in Jamaica. Possible reasons for these large prevalence differences are currently being investigated. (AU)

Prevalence of atopic eczema in Barbadian schoolchildren: preliminary findings from the Barbados National Asthma and Allergy Study - abstract

In 1995 and 1996 the Barbados National Asthma and Allergy Study, a questionnaire survey of all schoolchildren 6 - 7 years and aged 13 - 14 year, was conducted. The aim of the survey was to describe the prevalence and severity of asthma, rhinitis and eczema in children living in Barbados, to make meaningful comparisions with other countries (e.g Jamaica) and to obtain baseline measures for asessment of future trends in the prevalence and severity of this disease. The questionnaire sought to discover the presence of an itchy rash, persisting for more than six months, and in the typical anatomical distribution of atopic eczema. In addition, doctor diagnosed eczema was sought. Three thousand, eight hundred and ninety-four (3894) questionnaires were returned in the 6 - 7 years old age group (97 percent) and 3552 in the 13 - 14 year- old age group (88 percent). The prevalence of atopic eczema in the 6 - 7 year-old age group was 10.6 percent and in the 13 - 14 year-old age group was 10.0 percent. Diagnosis by a doctor reduced the prevalence to 6.2 percent in the primary school group and 3.6 percent in the secondary school group. This study has demonstrated for the first time in a Caribbean country the prevalence of this common childhood complaint. (AU)

London-born black Caribbean children are at increased risk of atopic dermatitis

BACKGROUND: Previous reports suggest that atopic dermatitis is more common in black Caribbean children born in the United Kingdom than in white children. It is unclear whether these differences are caused by selection bias or variations in the use of the word "eczema" in the groups studied. OBJECTIVE: Our objective was to explore ethnic group differences in the prevalence of atopic dermatitis in London schoolchildren. METHOD: A cross-sectional prevalence survey of 693 junior school children in three schools was performed. Atopic dermatitis was defined in three ways: (1) by a dermatologist, (2) by visible flexural dermatitis as recorded by an independent observer, and (3) by a history of flexural dermatitis according to the child's parents. RESULTS: The prevalence of atopic dermatitis according to examination by a dermatologist was 16.3 percent in black Caribbean children and 8.7 percent in white children. This increased risk was present for different methods of defining of atopic dermatitis and persisted after adjustment for potential confounders. CONCLUSION: London-born black Caribbean children appear to be at an increased risk of having atopic dermatitis. (AU)

Immunological abnormalities in HTLV-1 infected Jamaican children (abstract)

This paper reports on the immunological findings of a case control study of 50 infective dermatitis (ID) patients and 36 atopic eczema (AE) patients undertaken between December 1990 and August 1991. It also reports on a comparison of these results with those of age and sex matched normal controls, and age and sex matched HTLV-I infected asymptomatic children. Investigations of their immune systems showed that both ID and AE patients had normal responses to delayed hypersensitivity skin tests, and normal compliment levels. However there was a marked increase in the activity of both T and B lymphocyte systems, with all immunoglobulin levels being significantly increased in ID patients versus others. The CD4:CD8 ratio was increased, with an increase in the CD4 counts. Monoclonal antibody tests showed increased T cell activation. The results confirm immune dysfunction though the precise mechanism of the immunodysregulation remains to be determined. (AU)

Infective dermatitis of Jamaican children 1966-1991 - abstract

Infective dermatitis of Jamaican children, first described by Sweet in 1966, is a chronic eczema associated with persistent infection of the skin or anterior nares with either staphylococcus aureus or B haemolytic streptococcus, or both. In 1990, we reported a pilot study of 14 children with infective dermatitis (ID) and 11 with atopic eczema (AE) as controls, which showed that all the ID patients were positive for antibodies to the human T-lymhotrophic virus (HTLV-1). We postulated then that there was an association between HTLV-1 infection and infective dermatitis, and suggested that this organism might be causing ID through an immune mechanism. This paper reports on findings of a case control study of 50 ID patients and 36 AE patients undertaken between December, 1990 and August, 1991, which confirms the association between HTLV-I and infective dermatitis. All 50 patients with ID were positive for HTLV-I and antibodies, while the AC controls were all negative. In addition, when compared to the atopic controls, the ID patients had lower haemoglobins, higher white cell counts, and higher ESRs. They also had lower serum albumins and serum irons. Investigations of their immune systems showed that both groups had normal responses to delayed hypersensitivity skin tests, and normal complement levels. However, there was a marked increase in the activity of both T and B-lymphocyte systems, with all immunoglobulin levels being significantly increased in ID patients. The CD4: CD 8 ratio was increased, with an increase in the CD4 counts. Monoclonal antibody tests showed increased T-cell activation. The results confirm the association between HTLV-1 infection and infective dermatitis and confirm immune dysfunction. The precise mechanism of the immunodysregulation, however, remains to be determined (AU)