Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where A. Lahti is active.

Publication


Featured researches published by A. Lahti.


Contact Dermatitis | 1996

Guidelines for measurement skin colour and erythema A report from the Standardization Group of the European Society of Contact Dermatitis

Ann Fullerton; Torkel Fischer; A. Lahti; K.‐P. Wilhelm; Hirotsugu Takiwaki; Jørgen Serup

This report reviews individual‐related variables (age, sex, race, anatomical site. skin surface properties), intra‐ and interindividual variation (temporal, physical and mental activity, orthostatic effect, menstrual cycle/menopause), environment‐related variables (light conditions, temperature) and various instrument‐related variables that influence skin colour. CIE colorimetry (Minolta Chroma Meter) and spectrophotometric measurement (Derma Spectrometer) are considered. The guidelines give recommendations for measuring conditions and procedures.


Allergy | 1980

Extraction and Properties of Apple Allergens

Fred Björkstén; Liisa Halmepuro; Matti Hannuksela; A. Lahti

It is shown that apple allergens are probably proteins and that they can be extracted in an active form only if reactions with phenolic compounds present in apple are inhibited. This is accomplished by incorporating chelators and solid polyvinylpolypyrrolidone in the extraction medium. Phenol, commonly used as a preservative, should not be added. With the RAST, serum‐IgE antibodies capable of reacting with apple allergens were detected in 90% of patients with clinical apple allergy, in 44% of patients with clinical birch‐pollen allergy and in 5—10% of patients with other atopic allergies. RAST inhibition indicated that apple and birch‐pollen allergens cross‐react.


Contact Dermatitis | 2002

Monitoring levels of preservative sensitivity in Europe - A 10-year overview (1991-2000)

John Wilkinson; S. Shaw; Klaus Ejner Andersen; F. M. Brandão; Derk P. Bruynzeel; Magnus Bruze; José G. Camarasa; Thomas L. Diepgen; G. Ducombs; P. J. Frosch; A. Goossens; J-M Lachappelle; A. Lahti; Torkil Menné; Stefania Seidenari; Antonella Tosti; J. E. Wahlberg

A 10‐year multicentre analysis of the frequency of sensitivity to common preservatives collected in 16 centres in 11 countries has shown stable but persisting high levels of sensitivity to formaldehyde and 5‐chloro‐2‐methyl‐4‐isothiazolin‐3‐one + 2‐methyl‐4‐isothiazolin‐3‐one (MCI/MI). It has also revealed a significant increase in the level of reactivity to methyldibromoglutaronitrile (MDBGN) from 0.7% in 1991 to 3.5% in 2000. The current high level of sensitivity to MDBGN requires an urgent safety re‐evaluation and risk assessment update along with consideration of immediate lowering of use concentrations, especially in leave‐on products.


Contact Dermatitis | 1977

Immediate reactions to fruits and vegetables

Matti Hannuksela; A. Lahti

Common fruits and vegetables were tested as such with the “scratch‐chamber” method in 388 patients with various atopic disorders. Of the patients with hypersensitivity to birch pollen, 36% showed immediate positive responses to these natural, fresh materials. Apple, carrot, parsnip and potato elicited reactions more often than, e.g. swede, tomato, onion and parsley. On the basis of clinical data, the relevancy of the results of the skin tests was 80–90%. Both “false positive” and “false negative” responses were seen.


Contact Dermatitis | 1995

Patch testing with fragrances: results of a multicenter study of the European Environmental and Contact Dermatitis Research Group with 48 frequently used constituents of perfumes

P. J. Frosch; Beate Pilz; Klaus Ejner Andersen; D. Burrows; José G. Camarasa; A. Dooms-Goossens; G. Ducombs; Thomas Fuchs; M. Hannusksela; Jean-Marie Lachapelle; A. Lahti; H. I. Maibach; Torkil Menné; R. J. G. Rycroft; S. Shaw; J. E. Wahlberg; Ian R. White; J. D. Wilkinson

The objective of this study was to determine the frequency of reactivity to a series of commonly fragrances in dermatological patients. A total of 48 fragrances (FF) were chosen, based on the publication of Fenn in 1989 in which the lop 25 constituents of 3 types (1. perfumes, 2. household products, 3. soaps) of 400 commercial products on the US market had been determined. In a pilot study on a total of 1069 patients in 11 centres, the appropriate test concentration and vehicle were examined. For most fragrances, 1% and 5% were chosen, and petrolatum proved to be the best vehicle in comparison to isopropyl myristate and diethyl phthalate. In the main study, a set of 5 to 10 fragrances at 2 concentrations was patch tested in each centre on a minimum of 100 consecutive patients seen in the patch test clinic. These patients were also patch tested to a standard series with the 8% fragrance mix (FM) and its 8 constituents. In patients with a positive reaction to any of the 48 FF, a careful history with regard to past or present reactions to perfumed products was taken. A total of 1323 patients were tested in 11 centres. The 8% FM was positive in 89 patients (8.3% of 1072 patients). Allergic reactions to the constituents were most frequent to oak moss (24), isoeugenol (20), eugenol (13), cinnamic aldehyde (10) and geraniol (8). Reactions read as allergic on day 3/4 were observed only 10 × to 7 materials of the new series (Iso L: Super® (2), Lyral® (3), Cyclacet® (1), DMBCA (1), Vertofix® (1), citronellol (1) and amyl salicylate (1)). The remaining 41 fragrances were negative. 28 irritant or doubtful reactions on day 3/4 were observed to a total of 19 FF materials (more than 1 reaction: 5% citronellol (2), 1%amyl salicylate (2), 1%isononyl acetate (3), 0.1% musk xylol (2). 1%citral (2), and 1% ionone beta (2)). Clinical relevance of positive reactions to any of the FF series was not proved in a single case. This included the 4 reactions in patients who were negative to the 8% FM. In conclusion, the top 25 fragrances commonly found in various products caused few reactions in dermatological patients and these few appeared to be clinically irrelevant, with the possible exeption of Lyral®. However, this data should be interpreted in the light of the relatively small number of patients tested (only 100 in most centres).


Clinical and Experimental Immunology | 2008

Reduced frequency of nickel allergy upon oral nickel contact at an early age.

I. M. W. Hoogstraten; Klaus Ejner Andersen; B. M. E. Blomberg; D. Boden; D. P. Bruynzeel; D. Burrows; José G. Camarasa; A. Dooms-Goossens; G. Kraal; A. Lahti; Torkil Menné; R J G Rycroft; S. Shaw; D. Todd; K. J. J. Vreeburg; J. D. Wilkinson; R. J. Scheper

From animal studies we know that oral administration of T‐dcpcndcnt antigens before sensitization effectively induces systemic immune unresponsiveness. Such ‘oral tolerance’ is persistent, dose‐dependent, antigen‐specific and presumably T suppressor cell‐mediated. Oral tolerance induction could be an effective way to prevent undesired T cell‐mediated immune functions, such as playing a role in allograft reaction, autoimmune and allergic diseases. In the present study allergic contact hypersensitivity (ACH) to nickel, currently presenting the most frequent contact allergy in man, was chosen to establish the feasibility of oral prevention of undesired T cell‐mediated immunity in man. Potentially tolerizing (oral nickel contacts via orthodontic braces) as well as sensitizing (ear piercing) events were studied retrospectively in 2176 patients attending nine European patch test clinics. Patients were interviewed by means of a confidential questionnaire. The results show that ear piercing strongly favoured development of nickel ACH. More importantly, patients having had oral contacts with nickel‐releasing appliances (dental braces) at an early age, but only if prior to ear piercing, showed a reduced frequency of nickel hypersensitivity. Frequencies of other hypersensitivities, in particular to fragrance, were not affected. These results support our view that induction of specific systemic immunologic tolerance by timely oral administration of antigens is feasible in man.


Allergy | 1980

Allergy to Birch Pollen and Apple, and Gross-Reactivity of the Allergens Studied with the RAST

A. Lahti; Fred Björkstén; Matti Hannuksela

Apple‐pulp allergens arc unstable, but fresh material can be used for skin testing. In this study stable allergens, probably of a protein nature, were extracted from apple seed and used in radioallergosorbent tests (RAST). Apple‐seed allergens were shown by RAST inhibition to cross‐react with birch pollen allergen(s). Cross‐reactivity may explain the frequent co‐occurrence of birch pollen and apple allergy. Approximately 50% of patients in a group with immediate hypersensitivity to birch pollen were also sensitive to apple as judged by a history of symptoms, skin tests with apple‐pulp and apple‐seed preparations, and apple‐seed RAST.


Contact Dermatitis | 1993

Allergic reactions to a hairdressers’series: results from 9 European centres

P. J. Frosch; D. Burrows; José G. Camarasa; A. Dooms-Goossens; G. Ducombs; A. Lahti; Torkil Menné; R. J. G. Rycroft; S. Shaw; Ian R. White; J. D. Wilkinson

To obtain data on the frequency of sensitization among European hairdressers, the patch test results from 9 centres were evaluated. 8 allergens recommended by the ICDRG and EECDRG in the hairdressing series and PPD from the standard series were used to patch test 809 hairdressers and 104 clients suspected of contact sensitization. Among hairdressers, the mean frequencies of sensitization ranked as follows: GMT 19%, PPD 15%, APS 8%, PTD 8%, ONPPD 4%, and PADH 4%. In contrast to GMT in acid permanent waves, the frequency of sensitization to AMT in alkaline permanent waves was only 4%. Frequencies of sensitization to pyrogallol and resorcinol were 0.8% and 0.6%, respectively. The frequencies of sensitization showed marked regional variations, particularly that to GMT, which was highest in Germany (51%), followed by Spain (22%) and London (19%). Clients of hairdressers showed a similar rank order of sensitization frequency, with the exception of APS, which was completely negative in this (small) series.


Contact Dermatitis | 1996

Corticosteroid contact allergy: an EECDRG multicentre study

A. Dooms-Goossens; Ke. Andersen; Fm. Brandao; Derk P. Bruynzeel; D. Burrows; José G. Camarasa; G. Ducombs; P. J. Frosch; Matti Hannuksela; Jean-Marie Lachapelle; A. Lahti; Torkil Menné; J. E. Wahlberg; J. D. Wilkinson

This article describes the results of an EECDRG multicentre study on contact allergy to corticosteroids. A total of 7238 patients were investigated: 6238 in 13 centres in the course of 1993, and 1000 patients in 1 centre in 1993 and 1994. The 5 corticosteroids tested were budesonide 0.1% pet., betamethasone‐17‐valerate 1% pet., clobetasol‐17‐propionate 1% pet., hydrocortisone‐17‐butyrate 1% eth., and tixoeortol‐21‐pivalate 1%., pet.; 189 (2.6%) gave a positive patehtest reaction (+, ++, +++)to at least 1 of the corticosieroids. The data regarding the corticosteroid‐sensitive patients, as well as the patchtest results, were recorded on a standardized form.


Contact Dermatitis | 1995

Testing with fragrance mix. Is the addition of sorbitan sesquioleate to the constituents useful

Peter J. Frosch; Beate Pilz; Desmond Burrows; José G. Camarasa; Jean-Marie Lachapelle; A. Lahti; Torkil Menné; J. D. Wilkinson

In a multicentre study, the value of adding sorbitan sesquioleate (SSO) to the constituents of the 8% fragrance mix (FM) was investigated. In 7 centres, 709 consecutive patients were tested with 2 types of FM from different sources, its 8 constituents with 1% SSO, its 8 constituents without SSO, and 20% SSO. 5 patients (0.71%) reacted to the emulsifier SSO itself, read as definitely allergic on day 3/4. 53 patients reacted to either one of the mixes with an allergic type of reaction. When tested with the constituents without SSO, 41.5% showed an allergic reaction versus 54.7% with SSO. If both types of reactions were considered (allergic and irritant) 38.3% of 73 patients showed a positive “breakdown” result without SSO, versus 54.8% with SSO. The differences were statistically significant. Reactivity to FM constituents was changed in a specific pattern by addition of SSO‐irritant reactions increased, particularly for cinnamic alcohol, eugenol, geraniol, oak moss and hydroxycitronellal, whereas others showed only a slight change. Allergic reactions were also increased by SSO, but the rank order of the top 3 sensitizers (isoeugenol, oak moss and eugenol) did not change. Cinnamic alcohol was the only constituent with decreased reactivity after addition of SSO. A positive history of fragrance sensitivity (HFS) was clearly associated with a positive allergic reaction to either the mix or 1 of its constituents (51% versus 28.6% with a negative HFS). Irritant reactions were linked to a negative HFS in a high proportion (64.3%). In 17 patients, a repeated open application test (ROAT) was performed with a total of 43 patch‐test‐positive materials. The ROAT was positive in 20/31 (64.5%) tests in 11 patients with a positive HFS, but negative in all 6 patients with a negative HFS (0/12 tests). In conclusion, addition of SSO to the constituents of FM increases both irritant and allergic reactions, though the difference from the results obtained without SSO is not as high as previously reported. The ROAT is a valuable tool in validating such patch test results.

Collaboration


Dive into the A. Lahti's collaboration.

Top Co-Authors

Avatar

Torkil Menné

University of Copenhagen

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Klaus Ejner Andersen

University of Southern Denmark

View shared research outputs
Top Co-Authors

Avatar

P. J. Frosch

Katholieke Universiteit Leuven

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

José G. Camarasa

Autonomous University of Barcelona

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

S. Shaw

Wycombe General Hospital

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

A. Dooms-Goossens

Katholieke Universiteit Leuven

View shared research outputs
Researchain Logo
Decentralizing Knowledge