K. Lammintausta

Patch test reactions in atopic patients

Patch testing was carried out in 851 atopic patients: 181 atopic dermatitis (AD)patients were additionally tested with 50% dilutions of the test substances. The occurrence of allergic and irritant reactions was frequent, being 57% and 33% for AD patients aged 28–41 years and 19–27 years, respectively. Among age‐matched allergic rhinitis (AR)/allergic conjunctivitis (AC) or asthma (A) patients, the number of allergic reactions varied from 25 to 30%, and for irritant reactions was 24%. In all groups, nickel, fragrance‐mix, balsam of Peru and neomycin were the commonest allergens. Contact allergy to ingredients of topical medicaments was common among AD patients and patients with severe and long‐lasting dermatitis were most frequently sensitized. However, sensitivity to multiple substances was not common among those patients. The number of irritant reactions was considerable, but 50% dilution of the test substances did not solve the problem.

Occurrence of contact allergy and hand eczemas in hospital wet work

The occurrence of contact sensitivity and hand dermatitis was studied in hospital employees. The incidence of contact allergy was 21%. Nickel (9%) was the most common allergen followed by perfumes (6%).

Course of hand dermatitis in hospital Workers

The occurrence and course of hand dermatitis in hospital workers was studied on the basis of the patient register of an occupational specialist and by a clinical follow‐up study. About 1% of all the hospital workers had had dermatitis, cleaners, kitchen workers and nurses most frequently. 54% of the patients who were clinically studied had suffered from periodic symptoms and 35% had current hand dermatitis. Those who had previous or present atopic dermatitis had most frequently developed dermatitis during the first year of their service. An atopic constitution seemed to predispose to the development of permanent or periodic hand dermatitis. The patients with sensitivity to nickel or fragrances had relapses in the majority of cases.

Interrelationship of nickel and cobalt contact sensitization

The possible modulating effect of previous nickel sensitization on subsequent cobalt sensitization, and vice versa, was studied in a guinea pig model, using an open epicutanous induction protocol. Challenge tests were made by both topical and systemic routes, Controls included animals sensitized to only one of the metals.

Mast cells and IgE in intestinal mucosa in adult atopic dermatitis patients.

Duodenal biopsies from 29 adult atopic dermatitis (AD) patients with multiple positive skin prick test reactions were examined and the results compared with biopsies from 13 non‐atopic controls. The duodenal mucosa showed mild inflammatory changes in six out of the 29 patients, but was normal in all the controls. Numerous anti‐IgE positive cells, increasing with the severity of AD, were found in the duodenal mucosa in 25 of the 29 AD patients compared with few sporadic positive cells seen in only two out of 13 controls (P < 0. 001). The total serum IgE level showed a significant positive correlation with the number of anti‐IgE stained cells in the mucosa (P < 0.05). No significant differences were found in the total number of toluidine blue stained cells or cells immunoreactive for histamine between patients and controls. However, AD patients who had high numbers of anti‐IgE positive cells often had decreased numbers of histamine immunoreactive cells in the mucosa suggesting mast cell degranulation. These findings provide further evidence that also in adult AD patients the gastrointestinal tract may serve as a portal of entry for allergens which may lead to exacerbation of AD.

Experimental nickel sensitization in the guinea pig: comparison of different protocols

3 different sensitization protocols were compared for inducing delayed‐type nickel contact hypersensitivity in guinea pigs. Open epicutaneous sensitization (OE) induced nickel allergy in 11/22 (50%) guinea pigs. When intradermal injections of Freunds complete adjuvant into the nickel‐painted skin was added to the same protocol. 4/13 (31 %) became sensitized. The guinea pig maximization protocol induced nickel allergy in only 7/31 (23%) of the animals. Compared with the 2 other methods, animals sensitized with open epicutaneous applications reacted more rapidly (maximum at 6 h) and strongly (2+ reaction in 12/22 of animals) in previous patch lest sites upon systemic (i p.) nickel challenge. Open epicutaneous sensitization of guinea pigs should he a useful model for studying cellular and immunological mechanisms in nickel contact sensitivity.

Nickel sensitivity and the course of atopic dermatitis in adulthood.

The course of dermatitis was followed in nickel‐sensitive and nickel‐negative atopic and non‐atopic patients. Manifest dermatitis was seen in 70% of the nickel‐allergic and in 64% of the nickel‐negative female atopic dermatitis (AD) patients. Those atopic subjects who had minor symptoms in their teens suffered more from dermatitis if they had developed nickel allergy (p < 0.025). Hands and the head region were the most common sites for current dermatitis in both groups.

Nickel penetration in allergic individuals: bioavailability versus X‐ray micro‐analysis detection

Development of local allergic reactions after different application times with Finn Chambers was recorded in 34 nickel‐sensitive patients. Biologically significant amounts of nickel seemed to penetrate the skin within a few hours, although physical penetration was minimal. Nickel was detected only in the upper keratin cell layer with an X‐ray microanalysis method.

Langerhans' cell population in topical patch-test and systemic flare-up sites of nickel-sensitive guinea pigs.

Guinea pigs were sensitized to nickel by using the maximization method of Magnusson and Kligman (1969), challenged by topical and systemic applications of the allergen, and the epidermal Langerhans cell (LC) density studied with ATPase histochemistry.