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S H Wakelin

Publications and source records attributed to S H Wakelin.

At least 19 recordsLinked to original sources
PubMed2001

A retrospective analysis of contact allergy to lanolin.

BACKGROUND: Lanolin is often stated to be an important sensitizer but some of the available literature is based on the analysis of high-risk patients. OBJECTIVES: To analyse the frequency of contact allergy to lanolin (wool alcohols) in a central London teaching hospital patch-test population. METHODS: Review of 24,449 patients recorded on our database during 1982--96 who were tested with a standard series containing 30% wool alcohols. RESULTS: The mean annual rate of sensitivity to this allergen was 1.7%. The wool alcohols-allergic group contained a higher proportion of females (P < 0.05), and the mean age of both males and females (48.4 and 49.2 years) was higher than that of non-wool alcohols-allergic patients (41.4 and 35.9 years; P < 0.0005). There was no difference in atopic eczema status between these groups. The highest prevalence of allergy to wool alcohols was among patients with lower leg dermatitis (6.0%; 95% confidence interval, CI 4.46--7.54), followed by those with anogenital dermatitis (3.23%; 95% CI 1.81--4.65). There was an unexplained decline in the rate of positive patch tests to Amerchol L-101. However, some patients who reacted to this were negative with wool alcohols, so it may be a useful additional test reagent. The mean rates of allergy to Eucerin (0.65% per annum) and 50% hydrogenated lanolin in petrolatum (1% per annum) were low, and we no longer use these as test reagents. CONCLUSIONS: This study illustrates that lanolin sensitization has remained at a relatively low and constant rate even in a high-risk population (i.e. patients with recent or active eczema).

Adolescent↗
PubMed2001

Contact urticaria.

Contact urticaria has been reported following skin contact with a multitude of substances ranging from simple chemicals to macromolecules. Its prevalence amongst the general population is unknown, but it may be a relatively common and under-recognized phenomenon. Non-immunological (irritant) causes typically elicit mild localized reactions, which clear within hours. Such agents can be found widely in food, cosmetics and medicaments. The lower diagnostic end-point for nonimmunological contact urticaria has been the subject of debate, which makes interpretation of the literature difficult. Immunological (allergic) contact urticaria is due to immediate-type hypersensitivity, and occurs most commonly in atopic individuals. It is mediated primarily by histamine, and may be associated with systemic, and potentially life-threatening symptoms. Natural rubber latex is one of the most important causes today, and the recent 'epidemic' of latex protein allergy has helped draw attention to this subject. Immunological contact urticaria to animal or vegetable matter may occasionally affect those who handle food, and other occupations such as agricultural and veterinary workers. This may be associated with development of a protein contact dermatitis. The diagnosis of immunological contact urticaria can often be confirmed by simple investigations such as skin prick testing or measurement of specific IgE.

Dermatitis, Allergic Contact↗
PubMed2000

Association of TNFA gene polymorphism at position -308 with susceptibility to irritant contact dermatitis.

Mechanisms underlying susceptibility to skin irritants are not clearly understood. Cytokines play a key role in inflammation, and functional polymorphisms in cytokine genes may affect responses to irritants. We investigated the relationship between polymorphism in the tumor necrosis factor (TNF) alpha-chain gene and responses to irritants. Volunteers (n=221) tested with sodium dodecyl sulfate (SDS) and benzalkonium chloride (BKC) were divided into responders and nonresponders and high and low irritant-threshold groups. DNA was assayed for the TNF-308 polymorphism by a polymerase chain reaction-restriction fragment length polymorphism method. There was a significant increase in the A allele (P=0.030) and AA genotype (P=0.023) in both the SDS low irritant-threshold group and in SDS responders (A allele P=0.022, AA genotype P=0.048). In the BKC low irritant-threshold group, we found a significant increase in the A allele (P=0.002) and AA genotype (P=0.016). Individuals with a low threshold to both irritants demonstrated a significant increase (P=0.002) in the A allele. This is the first description of a nonatopic genetic marker for irritant susceptibility in normal individuals. Genotyping for the TNF-308 polymorphism may thus contribute to screening of individuals deemed at risk of developing irritant contact dermatitis.

Adolescent↗
PubMed2000

The frequency of fragrance allergy in a patch-test population over a 17-year period.

Fragrances are widely encountered in our daily environment and are known to be a common cause of allergic contact dermatitis. We have reviewed our patch test data from 1980 to 1996 to establish whether the pattern of fragrance allergy has changed with time. During this period, 25,545 patients (10,450 male, 15,005 female) were patch tested with the European standard series. The mean annual frequency of positive reactions to the fragrance mix was 8.5% in females (range 6.1-10.9) and 6.7% in males (range 5.1-12.9). Females were 1.3 times more likely to be allergic to fragrance (P < 0.001, 95% confidence interval, CI 1.17-1.41). Males with fragrance allergy were older than females by 5.6 years (mean age 48.2 vs. 42.6 years; P < 0.001, 95% CI 3.9-7.3). The incidence of a concomitant positive patch test to balsam of Peru in fragrance-sensitive patients showed wide variation, suggesting that it is not a reliable marker of fragrance allergy. There was a positive correlation between the isomers isoeugenol and eugenol. Oak moss remained the most common overall allergen throughout the study, positive in 38.3% of females and 35.6% of males who were tested to the constituents of the fragrance mix. During the period of the study the incidence of positive tests to oak moss increased by 5% yearly (P = 0.001, 95% CI 2.2-8.7). The frequency of allergic reactions to eugenol and geraniol remained relatively constant. Isoeugenol and alpha-amyl cinnamic aldehyde sensitivity increased and hydroxycitronellal showed a slow decline. There was a striking reduction in the frequency of sensitivity to cinnamic aldehyde (by 18% yearly; P < 0.001, 95% CI 14.3-21.0) and cinnamic alcohol (by 9% yearly; P < 0.001, 95% CI 5.2-12.9); these are now uncommon fragrance allergens. These data show temporal trends which may reflect the frequency of population exposure to individual fragrances.

Acrolein↗
PubMed2000

Descriptive epidemiology of hand dermatitis at the St John's contact dermatitis clinic 1983-97.

For 15 years, hand dermatitis accounted for a quarter of patients seen in this clinic. The highest proportion occurred in women aged 17-30 years. Overall, the male to female ratio was 0.8, which contrasts with population-based studies. Catering was most frequently associated with occupational hand dermatitis. Other frequent occupational associations included metalworking, hairdressing, healthcare and mechanical work.

Adult↗
PubMed2000

Generalized pustular psoriasis or drug-induced toxic pustuloderma? The use of patch testing.

Pustular psoriasis is a rare but serious form of psoriasis. Clinically it may be difficult to differentiate from a pustular drug reaction. We report a case of a generalized pustular eruption triggered by exposure to amoxycillin in a patient with chronic psoriasis. Patch testing to 1% and 5% amoxycillin preparation confirmed a delayed hypersensitivity reaction.

Amoxicillin↗
PubMed1999

Livedoid vasculitis: a manifestation of the antiphospholipid syndrome?

Livedoid vasculitis, otherwise known as segmental hyalinizing vasculitis or livedo reticularis with summer ulceration, is a chronic disease with lesions affecting the feet and lower legs. Early lesions show petechiae, but characteristic features are recurrent, bizarrely shaped ulcers that heal to leave hyperpigmentation and atrophie blanche. The aetiology of the disorder is unknown, but the histology shows fibrin deposition within both the wall and lumen of affected vessels. The absence of a sufficient perivascular infiltrate or leucocytoclasia argues against a vasculitis, being more in keeping with a thrombo-occlusive process. Four patients with livedoid vasculitis with ulceration are described, all of whom had associated raised anticardiolipin antibodies but no other evidence of systemic disease. We suggest that livedoid vasculitis may be a manifestation of the antiphospholipid syndrome and recommend that all patients are screened for this. We also discuss treatment options for this often resistant condition.

Adolescent↗
PubMed1999

Amoxycillin-induced flexural exanthem.

We describe a 37-year-old man who developed an acute, inflammatory flexural eruption shortly after taking amoxycillin, then erythema multiforme-like lesions on the palms and soles. The eruption resolved with systemic corticosteroids, and positive patch tests with amoxycillin supported a drug-induced aetiology. A few similar cases have been described as the 'baboon syndrome' or intertriginous drug eruptions. We draw attention to this rare, distinctive drug eruption.

Adult↗
PubMed1999

Natural rubber latex allergy.

Rubber is an important industrial and consumer product encountered in many household items and medical devices. Whereas the chemical additives used in its manufacture are well recognized as a cause of delayed-type hypersensitivity (allergic contact dermatitis), it is only during the past decade that immediate-type allergy to natural rubber latex (NRL) proteins (latex allergy) has emerged as a serious health issue. Frequent, prolonged wearing of NRL gloves, especially amongst health care workers, is a major risk factor for such sensitization. Latex allergy is now an important medical, occupational, medico-legal and financial problem, and it is essential that policies are developed to reduce it. Undiagnosed latex allergy is potentially very serious for patients. This article briefly overviews latex allergy with emphasis on the practical issues of diagnosis and management.

Allergens↗
PubMed1999

Cutaneous graft-versus-host-like reaction in systemic T-cell lymphoma.

We report a case of systemic T-cell lymphoma with cutaneous lesions showing histological features of a cutaneous graft-versus-host-like-reaction. Histology from liver, lymph node and bone marrow showed a malignant T-cell infiltrate. T-cell receptor gene rearrangement studies confirmed the diagnosis. A cutaneous graft-versus-host-like reaction has been reported with disseminated malignancy and one case has been reported with systemic lymphoma. Graft-versus-host disease normally occurs when lymphocytes from an immunocompetent donor are introduced into a histo-incompatible recipient who is incapable of rejecting them. In our patient a similar reaction may have occurred if the lymphoma was composed of cytotoxic cells or if a cell-mediated immune response against the malignant T-cells cross-reacted with epidermal keratinocytes. Alternatively the malignant T-cells could have been functionally active and induced a lichenoid reaction in the skin.

Aged↗
PubMed1999

Patch testing with natural rubber latex.

Immediate-type hypersensitivity to natural rubber latex (NRL) may be associated with chronic eczema, and it has recently been suggested that NRL should be used as a patch-test allergen. However, a standardized preparation does not exist, and experience of patch testing with this substance is extremely limited. The aims of our study were to investigate the patch-test response to different preparations of NRL amongst patients with suspected contact dermatitis. 608 patients were patch tested with a latex series which included wet and dry preparations of undiluted high-ammonia (HA) NRL and low-ammonia thiuram-containing NRL. Cutaneous reactions to 1 or more NRL patches were noted in 24 patients. None of these were strong allergic reactions (> +), and in 15 patients, the responses were only doubtful (?+). Positive patch tests were observed in 9 patients, and were probably due to concurrent thiuram allergy in 6. In the remaining 3 patients, the reactions had subsided by the 2nd reading and may have represented false positives. None of the patients showed consistent allergic reactions to all NRL patches, and most of the doubtful readings had resolved within 4 days, suggesting that they were irritant rather than weak allergic responses. Patch testing to dry HA latex was associated with the least number of reactions. We conclude that allergic patch test reactions to NRL are uncommon, and as reactions are usually weak and difficult to interpret, we suggest that patch testing with NRL should remain experimental until further studies have been undertaken.

Adolescent↗