Patients with positive patch test to formaldehyde can be safely vaccinated with formaldehyde-containing vaccines.

BACKGROUND: Prophylactic vaccination against influenza and other epidemic viruses is recommended for citizens above 65 years. Several vaccines may contain traces of formaldehyde and are contra-indicated in patients hypersensitive (in the broadest possible meaning) to formaldehyde. Thorough knowledge on the various subtypes of hypersensitivity is sparse among non-dermatologists and non-allergists, and therefore many patients are prevented from vaccination based on a positive patch test to formaldehyde. The purpose of this retrospective study was to investigate whether patients with positive patch test to formaldehyde subsequently receiving a formaldehyde-containing vaccine and developed a severe adverse reaction. METHODS/MATERIALS: From January 2000 to June 2021, 169 patients (>50 years) had a positive formaldehyde patch test at the Department of Dermatology and Allergy Center, Odense University Hospital and were included into this retrospective study. The electronic medical record was assessed for receipt of a formaldehyde-containing vaccine after patch test and for subsequent contact with the Acute Ward in the Region of Southern Denmark within 14 days after vaccination. RESULTS: Of the 158 patients residing in the Region of Southern Denmark, 130 patients were vaccinated with one or more formaldehyde-containing vaccines of whom 123 received an influenza vaccine. No contacts to the acute wards were identified. DISCUSSION: Although prospective studies would be beneficial, patients with positive patch test to formaldehyde can be safely vaccinated with formaldehyde-containing vaccines.

Regular support provided by dermatological nurses improves outcomes in patients with psoriasis treated with topical drugs: a randomized controlled trial.

BACKGROUND: Patient adherence to topical antipsoriatic drugs is often poor, leading to poor efficacy. Use of long-term support delivered by dermatological nurses to patients treated with topical drugs may improve outcome. AIM: To evaluate whether regular support from dermatological nurses improves outcome and treatment adherence in patients with psoriasis receiving topical medications. METHODS: We conducted a randomized controlled trial (RCT) (clinicaltrials.gov registration NCT04220554), in which patients received once-daily topical medications (containing corticosteroids and/or calcipotriol) for as long as their psoriasis was visible. The patients were randomly allocated to standard care by the dermatologist either with (n = 51) or without (n = 52) support from dermatological nurses. The nurse support intervention consisted of a structured dermatological consultation at baseline and Week 1, followed by contact with a nurse each month (in the outpatient clinic or by telephone). The primary outcome was severity of psoriasis, which was measured by the Lattice System Physician's Global Assessment (LS-PGA) and assessed by intention-to-treat analyses using linear mixed regression models for longitudinal data. Secondary outcomes were quality of life (measured by the Dermatology Life Quality Index; DLQI) and good adherence (defined as use of ≥ 80% of recommended doses). RESULTS: In total, 92 patients (89%) completed the 48-week trial period. The intervention group improved more than the nonintervention group from baseline to Week 24 in LS-PGA (2.21 vs. 1.28, P = 0.001) and in DLQI at Week 12 (6.50 vs. 1.55, P < 0.001). Differences between the two groups in favour of the intervention were observed throughout the study period. More participants in the intervention group had good adherence compared with the nonintervention group (36% vs. 14%, P < 0.001). CONCLUSION: Regular, continued patient support from dermatological nurses increased the efficacy of psoriasis treatment, improved quality of life and enhanced long-term adherence to topical antipsoriatic drugs. However, there is still room for more improvement.

Guidelines for diagnosis, prevention, and treatment of hand eczema.

BACKGROUND: Hand eczema is a common inflammatory skin disorder. Health care providers need continuously updated information about the management of hand eczema to ensure best treatment for their patients. OBJECTIVES: To update the European Society of Contact Dermatitis guideline on the diagnosis, prevention, and treatment on of hand eczema. METHOD: The Guideline Development Group (GDG) was established on behalf of the ESCD. A call for interest was launched via the ESCD website and via the ESCD members' mailing list. Appraisal of the evidence for therapeutic and preventive interventions was applied and a structured method of developing consensus was used and moderated by an external methodologist. The final guideline was approved by the ESCD executive committee and was in external review on the ESCD webpage for 1 month. RESULTS: Consensus was achieved for several statements and management strategies. CONCLUSION: The updated guideline should improve management of hand eczema.

Compositae sensitization in Danish children and adolescents.

BACKGROUND: Compositae plant sensitization in children is relatively frequent. From 1995-2006, we found a prevalence of 1.8% sesquiterpene lactone (SL) mix/parthenolide patch test positives among consecutive eczema patients <18 years. OBJECTIVES: To report the results of patch test screening for Compositae sensitization in patients <18 years in the last 13 years. METHODS: Children and adolescents <18 years, diagnosed with Compositae sensitization between 2007 and 2019, were included. RESULTS: Among 388 children tested, 12 (3%) were Compositae-sensitized, and 11 (2.8%) had positive reactions to SL mix. Compositae mix 5% pet. elicited positive reactions in six of seven patients tested, and dandelion extract 2.5% pet. in six of 10 patients tested. The mean age of the five girls and seven boys was 9.4 years and 11.7 years, respectively. Eleven children had a personal and one a family history of atopy, and 11 children had hand eczema. Only two were mono-sensitized to Compositae. CONCLUSIONS: SL mix is a suitable screening agent among children and adolescents in our area, well supplemented with Compositae mix 5% and dandelion extract. The study emphasizes the importance of Compositae screening in children with a personal and/or family history of atopy, hand eczema or widespread airborne dermatitis, summer exacerbation, and plant exposure.

Contact sensitization to florists' chrysanthemums and marguerite daisies in Denmark: A 21-year experience.

BACKGROUND: Both florists' chrysanthemums (Chrysanthemum cultivars) and marguerite daisies (Argyranthemum frutescens [L.] Sch.Bip. and its varieties and cultivars) are popular ornamental plants in Denmark. OBJECTIVES: To present results of aimed patch testing with chrysanthemum and marguerite daisy extracts in Danish patients with Compositae sensitization. METHODS: The results of patch testing with chrysanthemum extract 3% petrolatum (pet.) and marguerite daisy extract 3% pet. (and possibly 1% pet.) from 1998 to 2019 were analyzed. RESULTS: Altogether, 111/191 (58%) patients tested positive to chrysanthemum extract and 104/179 (58%) tested positive to marguerite daisy. The majority was recreationally exposed, and most reactions were considered relevant. Feverfew extract 1% pet., Compositae mix 5% or 6% pet., or parthenolide 0.1% pet. may cross-react with chrysanthemum; Compositae mix seems to be best at detecting sensitization to marguerite daisy. CONCLUSIONS: In areas where exposure to chrysanthemum or marguerite daisies is prevalent, it is suggested to include extracts of these plants in the plant series to improve diagnosis of, and advice to, Compositae-allergic patients.

Atopic diseases and type I sensitization from adolescence to adulthood in an unselected population (TOACS) with focus on predictors for allergic rhinitis.

BACKGROUND: While much is known on childhood atopic diseases, knowledge about persistence of atopic diseases from childhood to adulthood is limited. We therefore aimed to study the clinical course of atopic diseases and type I sensitization prospectively in an unselected cohort of adolescents followed into adulthood. METHODS: A cohort of unselected 8th-grade school children (mean age 14 years) established in 1995 and followed up in 2010 were evaluated with questionnaire, clinical examination, skin prick tests and measurements of specific IgE. RESULTS: The lifetime prevalence of atopic diseases was high and increased significantly from adolescence (31%) to adulthood (57%); particularly allergic rhinitis increased with an incidence rate of 17.5/1000 person-years. Childhood predictors for adult allergic rhinitis were atopic dermatitis, asthma and asymptomatic sensitization to pollen and house dust mite. Among those with asymptomatic sensitization in adolescence, 53%-78% developed allergic rhinitis in adulthood. Furthermore, type I sensitization increased significantly from adolescence to adulthood mostly due to increased sensitization to pollen. Type I sensitization was found mainly in those with allergic rhinitis. A high number of adults had oral allergy symptoms due to the high number of birch pollen allergic individuals. CONCLUSION: Persistence of atopic diseases in adulthood is common, and a high proportion of the adult population is sensitized giving a high prevalence of allergic rhinitis. Many with asymptomatic sensitization in adolescence will develop allergic rhinitis in adult life. The focus should be on prevention of atopic diseases and sensitization already in childhood.

Screening for Compositae contact sensitization with sesquiterpene lactones and Compositae mix 2.5% pet.

BACKGROUND: Compositae contact sensitization may be difficult to diagnose, because of a lack of reliable screening allergens. OBJECTIVES: To assess the suitability of Compositae mix II 2.5% pet. (CM2.5) as a screening mix in the baseline series combined with sesquiterpene lactone (SL) mix and parthenolide (PTH). METHODS: CM2.5 was added to the baseline series, which included SL mix and PTH 0.1% pet., in January 2015, and PTH was included in TRUE Test Panel 3 in October 2015. All Compositae-sensitive patients diagnosed or tested in the next 4 years were assessed. RESULTS: Altogether, 57 patients (2.7%) presented with Compositae allergy. On primary testing in 53 newly diagnosed patients, SL mix elicited positive reactions most frequently (53% positive), followed by CM2.5 (47% positive), and PTH (45% positive). CM2.5 and PTH pet. elicited a few irritant reactions. Three patients had late reactions. Altogether, 16 patients (28%) were not detected by any of the three screening agents. CONCLUSIONS: SL mix is an indispensable, although insufficient, screening mixture in Denmark. It may be relatively safely supplemented with CM2.5 and PTH in the TRUE Test system for screening, but, when Compositae sensitization is suspected, further extracts should be tested on the basis of the history.

Twenty-eight-day follow-up of patch test reactions to p-phenylenediamine and p-phenylenediamine dihydrochloride: A multicentre study on behalf of the European Environmental and Contact Dermatitis Research Group.

BACKGROUND: There is an ongoing discussion on whether routinely patch testing with p-phenylenediamine (PPD) 1.0% pet. is safe, owing to the risk of patch test sensitization. Late-appearing patch test reactions may reflect patch test sensitization, but may also be attributable to a low degree of pre-existing sensitization. OBJECTIVES: To follow the positive patch test reactions to PPD and its salt PPD dihydrochloride (PPD-DHC) in order to characterize reaction patterns concerning time and dose in PPD-sensitized individuals. METHODS: Volunteers with previous reactions to PPD 1.0% were included and patch tested with PPD and PPD-DHC in equimolar dilution series. There were then seven follow-up visits over a period of 28 days. RESULTS: Twenty-six volunteers completed the study, of whom 23 of 26 (88%) reacted to PPD 1.0%, and 69% reacted to PPD 0.32%. Altogether, 42% and 27% reacted to the corresponding equimolar concentrations of PPD-DHC. After day 7, no new reactions were observed to any concentration tested, either of PPD or of PPD-DHC. CONCLUSION: No late-appearing reactions to PPD or PPD-DHC were observed at any dose. There is a risk of missing contact allergy when the dose is decreased.

Anti-inflammatory potency testing of topical corticosteroids and calcineurin inhibitors in human volunteers sensitized to diphenylcyclopropenone.

AIMS: To quantify the anti-inflammatory potency of topical corticosteroids and topical calcineurin inhibitors by measuring the contact allergic response to a diphenylcyclopropenone (DPCP) challenge in de novo sensitized human volunteers. METHODS: Two randomized, double-blind, vehicle-controlled studies were performed encompassing 76 volunteers: 29 in the first and 47 in the second study. Topical drugs were applied pre- and/or post-treatment in block designs. The compounds were tested simultaneously under occluded patch tests covering DPCP-induced dermatitis. Inhibitory responses were assessed by visual scoring and measurements of the oedema thickness with ultrasound. RESULTS: When applied both before and after the DPCP challenge, significant anti-inflammatory effects were seen in descending order for tacrolimus 0.1% ointment, clobetasol propionate ointment, betamethasone valerate ointment and hydrocortisone butyrate ointment, while pimecrolimus cream, hydrocortisone ointment and vehicles had no significant effect. Only tacrolimus ointment (P < 0.01) demonstrated a consistent significant pre-treatment inhibitory effect compared with an untreated DPCP control. CONCLUSIONS: This human testing method in which the inflammation of experimentally induced allergic patch test reactions is quantified by objective measurement allows an analysis of the anti-inflammatory potency of not only topical corticosteroids, but also of drugs that have no effect on vasoconstriction. The method allowed comparison of the potencies of four topical corticosteroids and two calcineurin inhibitors.

Clinical patterns of Compositae dermatitis in Danish monosensitized patients.

BACKGROUND: Compositae dermatitis was originally described as airborne contact dermatitis. More recent studies have reported a wider clinical spectrum, but often in polysensitized patients. OBJECTIVE: To evaluate the clinical features of patients sensitized to Compositae only. PATIENTS/METHODS: Consecutive Compositae-sensitive eczema patients, tested between 1990 and 2015, who, at the patch testing session diagnosing their Compositae allergy, were found to be sensitized only to the plant family, were included. RESULTS: Altogether, 529 of 13 139 patients tested (4.0%) were sensitized to Compositae, and 95 (18% of these) were monosensitized. The majority had hand eczema, and 39 (44%) had a vesicular volar pattern. Eighty-one patients were classified into one of three groups of similar size: localized eczema, eczema of exposed skin, and localized eczema turning into widespread eczema. CONCLUSIONS: The prevalence of Compositae sensitization is continuously high in consecutive eczema patients. Sensitization may occur at any age. Clinical features in monosensitized patients vary, but, with continuing exposure, the patients may develop more widespread dermatitis similar to classic Compositae dermatitis. Avoidance may clear the exogenous part, but not endogenous aetiological factors such as vesicular hand eczema or possible photosensitivity. Thorough clinical assessment and patient education are important in reducing the impact of Compositae contact allergy.

Different concentrations and volumes of p-phenylenediamine in pet. (equivalent doses) are associated with similar patch test outcomes: a pilot study.

BACKGROUND: Concern about causing active sensitization when patch testing is performed with p-phenylenediamine (PPD) 1% pet. has led to a recommendation to use PPD 0.3% pet. as a potentially safer preparation. However, the dose per area of allergen delivered, and hence the risk of active sensitization, depend on the amount dispensed into the patch test chamber, which can vary widely. OBJECTIVE: To evaluate whether patch testing with equivalent doses of different concentrations of PPD in pet. is associated with similar outcomes. METHODS: Seventeen known PPD-sensitive subjects were patch tested with different volumes and concentrations of PPD in pet. that deliver the same allergen dose per unit area (6 mg of PPD 1% pet. and 20 mg of PPD 0.3% pet. in Finn Chambers®, both equivalent to ∼ 0.09 mg/cm2 ). RESULTS: Eleven patients (65%) had positive reactions to both doses; 4 patients (24%) had negative results [percentage agreement of 88% (15/17)]. One patient each had a positive reaction to only one dose. CONCLUSIONS: The 88% concordance suggests that dose per unit area is more important in determining reactions to allergens than the excipient volume dispensed. Patch testing with a smaller volume of 1% PPD may be a reasonable alternative to testing with 20 mg of 0.3% PPD.

Parthenolide in Danish biodynamic and organic milk: A new source of exposure to an allergenic sesquiterpene lactone.

BACKGROUND: The sunflower family of plants (Compositae = Asteraceae) is currently the most allergenic plant family worldwide, according to the number of sensitizing species. Secondary plant metabolites, including the allergenic sesquiterpene lactones present in Compositae plants, may occur in food items either through their presence in, or through contamination of, plant-based raw materials, or through their occurrence in products of non-plant origin. OBJECTIVE: To analyse biodynamic, organic and conventional milk for the presence of the sesquiterpene lactone parthenolide. METHODS: The content of parthenolide in the milk samples was investigated in dichloromethane extracts obtained by liquid-liquid extraction, followed by gas chromatography-mass spectrometry analyses. RESULTS: The concentration of parthenolide was 0.07 ±0.004 ppm in biodynamic milk, 0.05 ±0.002 ppm in organic milk, and not detectable (<0.002 ppm) in conventional milk. CONCLUSIONS: This is the first report of a potent contact allergen in milk. There seems to be an association between the time that the dairy cattle spend grazing and the amount of parthenolide detected. Although the concentration is low, it is estimated to be high enough to elicit dermatitis in the most sensitive persons by direct contact with the milk.

Allergic contact dermatitis caused by nail acrylates in Europe. An EECDRG study.

BACKGROUND: Allergic contact dermatitis (ACD) caused by nail acrylates, also including methacrylates and cyanoacrylates here, is being increasingly reported. METHODS: A retrospective study in 11 European Environmental Contact Dermatitis Research Group (EECDRG) clinics collected information on cases of ACD caused by nail acrylates diagnosed by aimed testing between 2013 and 2015. RESULTS: Among 18 228 studied patients, 136 had ACD caused by nail acrylates (0.75%; 95%CI: 0.60-0.90), representing 67.3% (95%CI: 60.4-73.7) of ACD cases caused by acrylates. There were 135 females and 1 male, with a mean age ± standard deviation of 36.7 ± 12.2 years; 59 (43.4%) were exposed as consumers, and 77 (56.6%) were occupationally exposed. Occupational cases were more frequent in southern Europe (83.7%), and were younger (mean age of 33.4 ± 8.9 years); most developed ACD during the first year at work (65.0%), and at least 11.7% had to leave their jobs. Skin lesions involved the hands in 121 patients (88.9%) and the face in 50 (36.8%), with the face being the only affected site in 14 (10.3%). Most patients reacted to two or more acrylates on patch testing, mainly to 2-hydroxyethyl methacrylate (HEMA) (92.5%), 2-hydroxypropyl methacrylate (88.6%), ethylene glycol dimethacrylate (69.2%), and ethyl cyanoacrylate (9.9%). CONCLUSIONS: Nail cosmetics were responsible for the majority of ACD cases caused by acrylates, affecting nail beauticians and consumers, and therefore calling for stricter regulation and preventive measures. As HEMA detects most cases, and isolated facial lesions may be overlooked, inclusion of this allergen in the baseline series may be warranted.

The gene expression and immunohistochemical time-course of diphenylcyclopropenone-induced contact allergy in healthy humans following repeated epicutaneous challenges.

The gene expression time-course of repeated challenge of contact allergy (CA) remains largely unknown. Therefore, using diphenylcyclopropenone (DPCP) as model allergen in healthy humans we set out to examine: (i) the monotonous and complex gene expression time-course trajectories following repeated DPCP challenges to find the predominant gene expression pattern, (ii) the time-course of cell infiltration following repeated DPCP challenges and (iii) the transcriptome of a repeated CA exposure model. We obtained punch biopsies from control and DPCP-exposed skin from ten DPCP sensitized individuals at 5-6 monthly elicitation challenges. Biopsies were used for microarray gene expression profiling, histopathology and immunohistochemical staining. Validation of microarray data by qRT-PCR was performed on 15 selected genes. Early gene expression time points were also validated in an independent data set. An increasing and decreasing trend in gene expression followed by a plateau was predominantly observed during repeated DPCP challenges. Immune responses reached a plateau after two challenges histopathologically, immunohistochemically and in the time-course gene expression analysis. Transcriptional responses over time revealed a Th1/Th17 polarization as three upstream regulators (IFN-γ, IL-1 and IL-17) activated most of the top upregulated genes. Of the latter genes, 9 of 10 were the same throughout the time course. Excellent correlations between array and PCR data were observed. The transcriptional responses to DPCP over time followed a monotonous pattern. This response pattern confirms and supports the newly reported clinical time-course observations in de novo-sensitized individuals showing a plateau response, and thus, there is concordance between clinical response, histopathology, immunohistochemistry and microarray gene expression in volunteers de novo-sensitized to DPCP.

Allergenic sesquiterpene lactones from cushion bush (Leucophyta brownii Cass.): new and old sensitizers in a shrub-turned-a-pot plant.

BACKGROUND: The Australian cushion bush (Leucophyta brownii) of the Compositae family of plants has become a popular pot and container plant. The plant produces the sesquiterpene lactone allergen calocephalin. OBJECTIVES: To assess the sensitizing potential of sesquiterpene lactones from cushion bush. PATIENTS/MATERIALS/METHODS: Eleven Compositae-sensitive patients were patch tested with seven sesquiterpene lactones isolated from cushion bush. RESULTS: Six of seven sesquiterpene lactones elicited positive reactions in 4 of 11 patients. CONCLUSIONS: The well-known sesquiterpene lactone pseudoivalin and its derivative pseudoivalin acetate, as well as calocephalin and tomentosin, were confirmed to be sensitizers, whereas leucophytalin A and 4α-hydroxy-5αH,10αH-1,11(13)-guaidien-8ß,12-olide were shown to be allergenic for the first time. The patch test reaction patterns seem to follow the chemical patterns, which may eventually make it possible to trace primary sensitizers and advise patients more precisely.

The epidemic of methylisothiazolinone: a European prospective study.

BACKGROUND: The use of methylisothiazolinone (MI) in cosmetic products has caused an unprecedented epidemic of MI contact allergy. Current data concerning exposures at a European level are required. OBJECTIVES: To describe demographics and MI exposures for European patients with MI contact allergy. METHODS: Eleven European dermatology departments from eight European countries prospectively collected data between 1 May and 31 October 2015 among consecutive patients who had positive patch test reactions to MI (2000 ppm aq.). RESULTS: A total of 6.0% (205/3434; range 2.6-13.0%) of patients had positive patch test reactions to MI. Dermatitis most frequently affected the hands (43.4%), face (32.7%), arms (14.6%), and eyelids (11.7%); 12.7% had widespread dermatitis. For 72.7% (149/205), MI contact allergy was currently relevant mainly because of exposure to cosmetic products (83.2%; 124/149). Of these 124 patients, 19.5% were exposed to leave-on and rinse-off cosmetic products, 24.8% only to leave-on cosmetic products and 38.9% only to rinse-off cosmetic products containing MI or methylchloroisothiazolinone/MI. The majority of these (79%) noted onset of their dermatitis between 2013 and 2015. Fifteen patients (7.3%) had previously experienced allergic reactions when they were in newly painted rooms. CONCLUSION: Clinically relevant MI contact allergy remains prevalent across European countries, mainly because of exposure to rinse-off and leave-on cosmetic products.

Persistent Skin Reactions and Aluminium Hypersensitivity Induced by Childhood Vaccines.

There is increasing awareness of reactions to vaccination that include persistent skin reactions. We present here a retrospective investigation of long-lasting skin reactions and aluminium hypersensitivity in children, based on medical records and questionnaires sent to the parents. In the 10-year period 2003 to 2013 we identified 47 children with persistent skin reactions caused by childhood vaccinations. Most patients had a typical presentation of persisting pruritic subcutaneous nodules. Five children had a complex diagnostic process involving paediatricians, orthopaedics and plastic surgeons. Two patients had skin biopsies performed from their skin lesions, and 2 patients had the nodules surgically removed. Forty-two children had a patch-test performed with 2% aluminium chloride hexahydrate in petrolatum and 39 of them (92%) had a positive reaction. The persistent skin reactions were treated with potent topical corticosteroids and disappeared slowly. Although we advised families to continue vaccination of their children, one-third of parents omitted or postponed further vaccinations.

Contact Allergy in Danish Healthcare Workers: A Retrospective Matched Case-control Study.

Contact dermatitis in healthcare workers is a world wide problem. We conducted a retrospective observational study of the patch-test results of 1402 healthcare workers and 1402 matched controls with contact dermatitis who were treated at 3 hospitals departments in Denmark between 2007 and 2014. The primary objective was to determine whether healthcare work was associated with contact allergy to thiuram mix. Unadjusted univariate analyses revealed that healthcare work was significantly associated with occupational contact dermatitis and hand dermatitis. Contact allergy to thiuram mix was more common in healthcare workers was significantly associated with having occupational contact dermatitis, hand dermatitis and older age. In conclusion, we report here a potential problem of contact allergy to thiurams in healthcare workers with contact dermatitis. Legislative authorities may in the future focus on the use of rubber accelerators in, for example, protective gloves, which are widely used by healthcare professionals.

Lettuce contact allergy.

Lettuce (Lactuca sativa L.) and its varieties are important vegetable crops worldwide. They are also well-known, rarely reported, causes of contact allergy. As lettuce allergens and extracts are not commercially available, the allergy may be underdiagnosed. The aims of this article are to present new data on lettuce contact allergy and review the literature. Lettuce is weakly allergenic, and occupational cases are mainly reported. Using aimed patch testing in Compositae-allergic patients, two recent Danish studies showed prevalence rates of positive lettuce reactions of 11% and 22%. The majority of cases are non-occupational, and may partly be caused by cross-reactivity. The sesquiterpene lactone mix seems to be a poor screening agent for lettuce contact allergy, as the prevalence of positive reactions is significantly higher in non-occupationally sensitized patients. Because of the easy degradability of lettuce allergens, it is recommended to patch test with freshly cut lettuce stem and supplement this with Compositae mix. As contact urticaria and protein contact dermatitis may present as dermatitis, it is important to perform prick-to-prick tests, and possibly scratch patch tests as well. Any person who is occupationally exposed to lettuce for longer periods, especially atopics, amateur gardeners, and persons keeping lettuce-eating pets, is potentially at risk of developing lettuce contact allergy.