Skin manifestations associated with toxocariasis: a case-control study

BACKGROUND: Human toxocariasis is one of the most common zoonotic helminthiases. The recent development of sensitive and specific diagnostic laboratory tests has led to identify a large spectrum of diseases, including cutaneous diseases, induced by Toxocara infection. Objective: The purpose of our study was to assess the risk of having a positive Toxocara ELISA test in patients with different cutaneous symptoms. METHODS: The diagnosis of toxocariasis was based on an ELISA test which was performed in 653 patients suffering from different skin conditions during a prospective case-control study. RESULTS: The excess of risk (adjusted odds ratio) of having a positive result in the Toxocara ELISA was statistically significant for 134 patients with urticaria (whatever the clinical presentation) and for 22 patients with prurigo compared to a control group (249 patients). No statistical excess of risk was observed for patients with atopic dermatitis, pruritus or non-atopic eczema. CONCLUSION: The authors conclude that patients suffering from urticaria or prurigo should be tested for Toxocara infection. Whether these patients should be treated with anthelminthic drugs remains to be determined in further studies.     

Tissue parasites in patients with chronic urticaria

Chronic urticaria is an important diagnostic and therapeutic problem. We aimed to investigate the sero-prevalence of tissue parasites causing toxocariasis and fasciolosis in patients with chronic urticaria. All cases were analyzed for antibodies against Toxocara canis and Fasciola hepatica by modified (homemade) ELISA. The excretory/secretory products of Toxocara and Fasciola were used as antigens (ES-ELISA) in the test. In this study, the highest toxocariasis seropositivity (29.0%) rate and the highest fasciolosis seropositivity (14.5%) rate were found in patients with chronic urticaria. Fasciolosis seropositivity and total seropositivity of toxocariasis and fasciolosis in patients with chronic urticaria was significantly higher than in healthy controls (p<0.05). Toxocariasis seropositivity in patients with chronic urticaria was not significantly higher than that in healthy controls (p>0.05). We suggest that parasitic infections should be considered as an important cause of chronic urticaria. Serological methods should be used to expose the diagnosis of tissue parasites in such cases.     

Therapeutic effects of antibacterial treatment for intractable skin diseases in Helicobacter pylori-positive Japanese patients

In order to understand the pathogenic relationship between Helicobacter pylori (H. pylori) and skin diseases, we examined the serum levels of IgG antibody against H. pylori and then performed gastroscopic examinations in Japanese patients with chronic skin diseases. These H. prylori-positive patients were treated with antibacterial eradication therapy, and therapeutic efficacy was evaluated. A total of 198 patients who were resistant to conventional therapies were randomly selected. They included 50 cases with chronic urticaria, 32 with pruritus cutaneous, 74 with atopic dermatitis, 15 with nummular dermatitis, 17 with prurigo chronica multiformis, 6 with psoriasis vulgaris, and 4 with erythroderma. Positive anti-H. pylori antibody was detected in 102 out of these 198 patients; more than half of the ones with chronic urticaria, pruritus cutaneous, nummular dermatitis, and prurigo chronica multiformis had positive antibodies. Gastroscopy was then performed in 48 cases with positive antibodies. Eradication therapy was effective in 60% of the patients with chronic urticaria, in 58% with pruritus cutaneous, in 54% with nummular dermatitis, and in 50% with prurigo chronica multiformis. In chronic skin diseases, persistent infection with H. pylori may be an eruption trigger and may cause deterioration of the disease into an in tractable and chronic form.     

Clinical study of the relationship between Helicobacter pylori and chronic urticaria and prurigo chronica multiformis: effectiveness of eradication therapy for Helicobacter pylori

Eighty two patients with chronic urticaria and 17 patients with prurigo chronica multiformis were referred to our department from October 2004 to February 2007 and were tested for Helicobacter pylori antigen using the polyclonal H. pylori stool antigen test (enzyme‐linked immunosorbent assay method). H. pylori antigen was detected in 25 (30.5%) of the 82 patients with chronic urticaria and in 10 (58.8%) of the 17 patients with prurigo chronica multiformis. Those findings were not significantly higher than the positive rate for H. pylori stool antigen in healthy age‐matched controls. In patients positive for H. pylori antigen, seven of the 25 with chronic urticaria had complications of gastritis (six patients) or gastric ulcers (one patient). Three of the 10 patients with prurigo chronica multiformis had complications of gastritis (two patients) or gastric ulcers (one patient). We examined the therapeutic efficacy of antibacterial treatment for the 17 patients with chronic urticaria and the eight patients with prurigo chronica multiformis who were positive for H. pylori antigen and accepted the treatment based on informed consent. We evaluated the effectiveness of treatment by scoring the skin conditions and by using the Skindex‐16, a measure of quality of life. The eradication therapy for H. pylori was more effective for treating prurigo chronica multiformis and the skin symptoms started to improve within 3–14 days after the therapy. However, that therapy was not always effective for treating chronic urticaria. We suggest that H. pylori may be an important pathogenetic factor, especially for prurigo chronica multiformis, and that eradication therapy should be considered to treat intractable cases.     

Occupational dermatoses in health care workers evaluated for suspected allergic contact dermatitis

Background:  Occupational skin diseases, including allergic contact dermatitis (ACD), irritant contact dermatitis, and allergic contact urticaria (ACU), occur commonly among health care workers (HCWs).
Purpose:  To evaluate the aetiology of the various skin diseases afflicting HCWs evaluated for suspicion of ACD and/or ACU and to identify the most common allergens among HCWs found to have ACD and/or ACU.
Methods:  A total of 1434 patients underwent patch testing. The demographic data and most common allergens for HCWs ( n  = 100) and non-HCWS ( n  = 1334) were compared.
Results:  HCWs were statistically more likely than non-HCWS to be female, have hand dermatitis, and have a history of atopy. HCWs were also more likely to have work-related ACD especially to quaternium-15, thiuram, carba mix, glutaraldehyde and benzalkonium chloride, and to have ACU to latex.
Limitations:  This study was retrospective and is subject to the resultant biases of all such investigations. Only patients suspected of having ACD and who underwent patch testing are included in our database. The prevalence of ACD and ACU is likely to be higher than that seen in the general HCW population.
Conclusions:  Our results underscore the importance of thoroughly evaluating HCWs for ACD and ACU with the use of expanded standard allergen series and prick or radioallergosorbent testing to latex.     

The treatment of facial atopic dermatitis in children who are intolerant of, or dependent on, topical corticosteroids: a randomized, controlled clinical trial

Background  Atopic dermatitis (AD) is most prevalent in areas of reduced skin barrier reserve, like face and neck, especially in children. Treatment with topical corticosteroids (TCS) is limited due to heightened risk of treatment-associated side-effects, thus necessitating alternative AD therapies.
Objectives  The primary study objective was to determine the efficacy of pimecrolimus cream 1% in children with mild–moderate facial AD dependent on/intolerant of TCS. Secondary objectives included effects on overall Eczema Area and Severity Index (EASI), head/neck EASI, pruritus severity and time to clearance of facial AD.
Methods  A multicentre, double-blind (DB) study of ≤ 6 weeks, followed by a 6-week, open-label (OL) phase was conducted. Two hundred patients (aged 2–11 years) were randomized 1 : 1 to pimecrolimus cream 1% ( n  =   99) or vehicle ( n  =   101) twice daily until clearance of facial AD or for a maximum of 6 weeks (DB phase). Sixteen patients receiving vehicle were allowed to switch to the OL phase at day 22.
Results  Significantly more pimecrolimus-treated vs. vehicle-treated patients were cleared/almost cleared of facial AD (Investigators' Global Assessment 0/1): 74·5% vs. 51·0%, P  <   0·001 (day 43) [57·1% vs. 36·0%, P  =   0·004 (day 22)]. Median time to clearance was 22·0 vs. 43·0 days (pimecrolimus vs. vehicle, respectively). Statistically significant differences for pimecrolimus vs. vehicle were also seen on head/neck EASI, overall EASI, and head/neck pruritus scores. Adverse events were mainly mild–moderate, occurring with similar frequency in both treatment groups.
Conclusions  In children with facial dermatitis intolerant of/dependent on TCS, pimecrolimus cream 1% effectively controls eczema and pruritus and is well tolerated.     

Comparison of cutaneous manifestations in systemic polyarteritis nodosa and microscopic polyangiitis

Background  The cutaneous manifestations of microscopic polyangiitis (MPA) and polyarteritis nodosa (PAN) have not been compared since their distinction.
Objectives  To compare the clinical and pathological cutaneous manifestations in a series of patients with systemic MPA and PAN.
Methods  Patients with MPA ( n  =   162) and PAN ( n  =   248) from the database of the French Vasculitis Study Group were diagnosed according to the American College of Rheumatology and/or the Chapel Hill Consensus criteria. Purpura, livedo, nodules, urticaria, skin necrosis, oral and genital ulcers were recorded when present. Fifty-five skin biopsies were analysed. Clinical and histological skin data were compared in the following groups: MPA, PAN and two PAN subsets: PAN with and PAN without hepatitis B infection. The prevalence of systemic and biological manifestations were analysed in relation to the presence or absence of skin lesions. The χ² test was used for statistical studies.
Results  Cutaneous manifestations were present in 44% of MPA and PAN. Purpura was the most frequent manifestation (26% cases of MPA vs. 19% cases of PAN, P  =   0·026). Urticaria was more frequent during PAN (6% vs. 1·2%, P  =   0·015). Skin lesions were more frequent during PAN in the absence of HBV infection (54% vs. 30%, P  <   0·05). No significant difference was detected from the histological data. Patients with skin lesions (either MPA or PAN) presented arthralgias and ocular manifestations more frequently. Mononeuritis multiplex was associated with skin lesions in the MPA group ( P  <   0·05).
Conclusions  The clinical or histological analysis of cutaneous lesions is not helpful for distinguishing PAN from MPA.     

Microanalysis of an antimicrobial peptide, beta-defensin-2, in the stratum corneum from patients with atopic dermatitis

Background  Antimicrobial peptides, such as defensin and cathelicidin, have recently been reported to play important roles in host defence and in cutaneous innate immunity. Although β-defensin-2 has been reported to be downregulated in the skin of patients with atopic dermatitis (AD), little is known about its role in the colonization of Staphylococcus aureus in the stratum corneum of patients with AD. A precise evaluation of these peptides in the stratum corneum as an antimicrobial barrier against S. aureus colonization has not yet been performed.
Objectives  To compare β-defensin-2 levels in the skin of patients with AD and healthy controls.
Methods  We developed a microanalytical technique to measure β-defensin-2 in the stratum corneum using a combination of immunoprecipitation and Western blotting.
Results  β-Defensin-2 in the stratum corneum was significantly higher in AD lesional skin compared with healthy control skin. The β-defensin-2 content in AD lesional skin also increased in proportion to the severity of the disease. Counting bacterial colonies revealed higher populations of S. aureus on lesional and nonlesional skin surfaces of patients with AD compared with healthy controls. Comparison of S. aureus colony numbers and β-defensin-2 levels demonstrated a positive correlation ( r  =   0·342, P  =   0·004, n  =   67) between both factors.
Conclusions  Collectively, these findings suggest that β-defensin-2 is induced in response to bacteria, injury or inflammatory stimuli and is not associated with vulnerability to S. aureus colonization in the skin of patients with AD.     

Efficacy of UVA1 phototherapy in 230 patients with various skin diseases

OBJECTIVE: Investigation of the efficacy of ultraviolet (UV) A1 phototherapy on atopic eczema, scleroderma, granuloma annulare, urticaria pigmentosa, prurigo nodularis, lichen sclerosus et atrophicus, T-cell lymphoma, keratosis lichenoides chronica, chronic urticaria and some rare, sclerosing skin diseases. METHODS: The data of 230 patients treated with low-dose, medium-dose and high-dose UVA1 therapy during 6 years were retrospectively analysed. The mean single dose (J/cm(2)), the mean number of irradiations and the mean total dose (J/cm(2)) were evaluated. The efficacy of phototherapy was assessed by a grading scale and the number of patients was given in percentage for each group. RESULTS: Good therapeutic effects of UVA1 therapy were shown in patients with atopic eczema, scleroderma, lichen sclerosus et atrophicus, keratosis lichenoides chronica, prurigo nodularis and with cutaneous T-cell lymphoma. Positive effects in some patients were seen in the urticaria pigmentosa and granuloma annulare group, no change to slight improvement was seen in most of the patients with rare, sclerosing skin diseases and no effect was seen in the chronic urticaria group. CONCLUSION: Besides topical and systemic therapy, UVA1 radiation is a good option of treatment in various skin diseases. It is one of the first-line treatments for several sclerotic diseases and it often improves pruritus considerably.     

Anti-interleukin-31-antibodies ameliorate scratching behaviour in NC/Nga mice: a model of atopic dermatitis

Background:  Interleukin-31 (IL-31), a novel cytokine, is upregulated in atopic dermatitis skin lesions in humans and skin lesions in the NC/Nga mice, a murine model for atopic dermatitis.
Objective:  Here, we investigated the effect of a monoclonal IL-31 antibody on scratching behaviour, weight gain and dermatitis in NC/Nga mice.
Methods:  Mice were divided into three groups, n  =   10 in each group. Mice were given monoclonal IL-31 rat-anti-mouse antibody 10 mg/kg or albumin intraperitoneally every fifth day for seven weeks. In addition, the mice in one group were not exposed to any form of intervention. The dermatitis score was clinically assessed twice a week. The scratching behaviour was automatically detected and objectively evaluated.
Results:  Intervention with IL-31 antibody 10 mg/kg intraperitoneally every fifth day in NC/Nga mice from age 7 weeks reduced the scratching behaviour, but did not have any impact on weight gain or dermatitis.
Conclusion:  IL-31 antibody reduces scratching behaviour in an atopic dermatitis-like murine model during the onset of clinical skin manifestations. Our findings suggest IL-31 antibody as a new potential therapeutic approach for pruritus in atopic dermatitis and other pruritic diseases.     

Behandlung von Pruritus als Symptom von Hauterkrankungen mit dem Serotonin‐Rezeptorantagonisten Ondansetron

Background: Pruritus is often a stressing symptom and a therapeutic challenge. We report our experience with the serotonin receptor antagonist ondansetron in the symptomatic treatment of pruritus accompanying various skin diseases. Patients and Methods: The influence of ondansetron (8 – 12 mg orally per day) on pruritus was assessed in twelve patients with various skin disorders. The intensity of pruritus was quantitated daily by a visual analogue scale over the time period of one week before, during, and one week after treatment. Results: Ondansetron decreased pruritus intensity in prurigo simplex (four patients), asteatotic eczema (two patients), parapsoriasis en plaques, and pruritus of unknown origin (one patient each). One of two patients with atopic dermatitis experienced relief, whereas no benefit was observed in urticaria factitia and notalgia paraesthetica (one patient each). Conclusions: Ondansetron may ameliorate the concomitant pruritus of some dermatologic diseases.     

Pruritus bei systemischen Erkrankungen

Chronic pruritus is a symptom of various internal disorders. In contrast to dermatological diseases, pruritus does not present with primary skin alterations in these patients. However, intense scratching may cause secondary skin changes such as abrasion, excoriation, prurigo nodularis, or in rare cases even scaring. The most common internal medicine causes for chronic pruritus are chronic kidney disease, hepatobiliary and hematological disorders as well as adverse drug reactions. Pruritus is less commonly seen in patients with endocrine or metabolic diseases, malabsorption syndromes, infectious diseases and solid tumors. The pathogenesis of pruritus in these disorders remains largely elusive, albeit preliminary insights have been gained for uremic and cholestatic pruritus. Antipruritic treatment is therefore symptomatic in most cases and may represent a clinical challenge. The calcium channel blockers gabapentin and pregabalin have the best proven efficacy in chronic kidney disease-associated pruritus. In Japan nalfurafine, a κ-opioid receptor agonist, has been licensed for this indication. UVB light may also attenuate uremic symptoms. In patients suffering from hepatobiliary disorders the sequestrant cholestyramine and the enzyme inducer rifampicin are effective. Furthermore, μ?opioid receptor antagonists and sertraline may be used to ameliorate cholestatic pruritus. So far, no randomized controlled trials have been performed for chronic itch in other internal medicine disorders. Antipruritic treatment is mainly based on effective therapy of the underlying disease.     

The use of a responder analysis to identify clinically meaningful differences in chronic urticaria patients following placebo- controlled treatment with rupatadine 10 and 20 mg

Background  According to the EAACI/GA²LEN/EDF guidelines for urticaria management, modern non-sedating H1-antihistamines are the first-line symptomatic treatment for chronic urticaria. Two previous randomized clinical trials demonstrated rupatadine efficacy and safety in chronic urticaria treatment. However, a responder analysis to identify clinically meaningful differences in patients with chronic urticaria has not yet been performed.
Methods  This analysis includes the pooled data from two randomized, double-blind, placebo-controlled, multicentre studies in which chronic urticaria patients were treated with rupatadine at different doses. Responder rates were defined as the percentage of patients after 4 weeks of treatment who exhibited a reduction of symptoms by at least 50% or 75% as compared to baseline. The variables analysed were as follows: Mean Pruritus Score (MPS), Mean Number of Wheals (MNW), and Mean Urticaria Activity Score (UAS).
Results  A total of 538 patients were included. This responder analysis, using different response levels, shows that the efficacy of rupatadine 10 mg and 20 mg is significantly better as compared to placebo in the treatment of chronic urticaria patients. Notably, treatment with rupatadine 20 mg daily resulted in a higher percentage of patients with response of 75% symptom reduction or better than rupatadine 10 mg.
Conclusion  Our results support the use of higher than standard doses of non sedating antihistamines in chronic urticaria. We strongly recommend performing and reporting responder analyses for established and new drugs used by patients with chronic urticaria.     

Effectiveness, side-effects and period of remission after treatment with methotrexate in localized scleroderma and related sclerotic skin diseases: an inception cohort study

Background  Detailed information is lacking on effectiveness of methotrexate (MTX) in sclerotic skin diseases, side-effects, and duration of remission after discontinuation.
Objectives  To determine effectiveness, side-effects and period of remission gained by use of MTX in sclerotic skin diseases.
Methods  All patients with a sclerotic skin disease who were treated with MTX (group A) or MTX with corticosteroids (CS) (group B) between 1995 and 2007 were evaluated. Detailed information was collected on dosage and duration of MTX treatment, concomitant immunosuppressive medication and CS treatment, effectiveness, side-effects, duration of the remission period, and time until restart.
Results  Fifty-eight patients (A, n  =   47; B, n  =   11) were evaluated. Clinical assessment revealed that 38 patients (81%) treated with MTX and 11 patients (100%) treated with MTX + CS showed improvement of sclerotic skin. After one treatment course 51% of the patients treated with MTX and 73% treated with MTX + CS reached remission status with a median follow-up time of 55 and 58 months. Patients showing relapse still responded to a second and even to a third course of MTX. Patients who showed a relapse had received a lower cumulative dose, due to a shorter period of treatment with MTX in the first course. Serious side-effects were seen in six patients (10%).
Conclusions  MTX was an effective treatment for various sclerotic skin diseases with a long period of remission and relatively low toxicity. Patients showing relapse still responded to a second and third course of MTX.     

Helicobacter pylori infection in skin diseases: a critical appraisal

More than 50% of the human population have long-term Helicobacter pylori infection, causing, in some cases, severe diseases such as peptic ulcers and stomach cancer. In the last few years several extra-gastrointestinal disorders have been associated with H. pylori infection. This review summarized the current medical literature, identified through hand searching and MEDLINE research, including our own studies, with regard to H. pylori and skin diseases. From the literature it can be seen that the role of H. pylori in skin diseases is still a controversial subject. Randomized controlled trials with adequate masking and sample sizes are still lacking. The best evidence comes from studies investigating chronic urticaria in which chronic urticaria disappeared in many patients with H. pylori infection after careful eradication of the H. pylori. Moreover, there are promising recent reports of beneficial H. pylori eradication in Behçet’s disease, pruritus cutaneus, prurigo chronica, prurigo nodularis and in some patients with lichen planus, but not in rosacea or psoriasis. Before any conclusions with respect to other skin diseases such as atopic dermatitis, Schoenlein-Henoch Purpura, Sweet’s syndrome, Sjögren syndrome or systemic sclerosis may be drawn, additional randomized, double-blinded and placebo-controlled studies including adequate diagnostic schedules, sufficient eradication treatment protocols, confirmation of eradication and adequate control groups are needed. The cutaneous pathology of H. pylori is far from being clear, but it is speculated that the systemic effects may involve increased mucosal permeability to alimentary antigens, immunomodulation, an autoimmune mechanism or the impairment of vascular integrity.     

Skin diseases in patients with β-thalassemia major

Background  β-Thalassemia major affects multiple organs and is associated with considerable morbidity and mortality. The goal of this analysis was to document the frequency of skin diseases among patients with β-thalassemia major.
Methods  A sample of 78 patients with β-thalassemia major was recruited and interviewed at the thalassemia clinic between April and June 2008. A dermatologist completed a skin examination of each patient and recorded any skin disease present. The patients' laboratory results and treatment modalities were recorded from the charts.
Results  Sixty-five (83.3%) of the 78 patients examined had a diagnosed skin disease: pruritus (37.2%), xerosis (34.6%), scars (24.4%), ephelides (23.1%), skin irritation/erythema caused by deferoxamine pump (12.8%), idiopathic guttate hypomelanosis (6.4%), pityriasis alba (6.4%), tinea infections (5.1%), verruca vulgaris (5.1%), urticaria (3.8%), hyperhidrosis, contact dermatitis, and acne (2.6%), necrobiosis lipoidica (1.3%), melasma (1.3%), and others (14.1%). Pruritus and xerosis increased in frequency with age. The mean serum ferritin level was higher in patients with xerosis than in those without (5607.7 ± 2997.5 ng/mL and 4285.2 ± 4732.4 ng/mL, respectively) ( P  = 0.005). Moreover, xerosis was observed significantly more frequently in patients using deferoxamine and deferiprone than in those using deferasirox ( P  = 0.047, P  = 0.027, and P  = 0.273, respectively).
Conclusion  Skin diseases, especially pruritus and xerosis, are observed highly frequently in patients with β-thalassemia major. Treatment is needed for these patients who already have other significant morbidities.     

Severity of disease, rather than xerosis, correlates with pruritus in patients with atopic dermatitis

Background  Atopic dermatitis (AD) is a chronic, relapsing skin disease characterized by xerosis and pruritus. As pruritus is an unpleasant sensation and the associated scratching aggravates the skin eruption considerably, it is important to control this symptom when treating AD. Dry skin is generally considered to be a potential cause of pruritus in xerotic skin diseases, but a clear correlation between pruritus and atopic xerosis has not been demonstrated.
Aim  To examine the contribution of atopic xerosis to the development of pruritus in AD.
Methods  Twenty-two patients with AD (12 males and 10 females; mean age, 27.5 years) were examined. Xerosis and the severity of disease were evaluated using the Objective Severity Assessment of Atopic Dermatitis (OSAAD) and the SCORing Atopic Dermatitis (SCORAD) index, respectively. A modified SCORAD index was calculated by removing the symptoms potentially associated with pruritus (intensity of itching and insomnia) from the standard SCORAD index. Pruritus was evaluated using both a visual analog scale and the Verbal Itch Score.
Results  The severity of AD (modified SCORAD index) correlated better than atopic xerosis (OSAAD score) with both pruritus scores, possibly indicating that the use of appropriate anti-inflammatory agents may be helpful in controlling pruritus as well as skin eruption in AD.
Conclusion  Our data suggest that the severity of disease (or skin inflammation) provides a greater contribution than xerosis to the development of pruritus in AD.     

Reactivity to autologous serum skin test and relationship with complement levels in chronic idiopathic urticaria and angio-oedema

Background.  A role for complement in autoantibody-mediated histamine release in urticaria has been suggested but not proven in vivo .
Aim.  To study serum complement levels in patients with chronic idiopathic urticaria (CIU) and to determine whether there was a relationship with autologous serum skin test (ASST) reactivity.
Methods.  We recruited 35 patients with CIU. Complement (C3, C4) levels and ASST were measured in all patients; additional investigations were undertaken dependent on history and examination.
Results.  Complement concentrations were outside the population reference intervals in 19/35 patients, with low C3 noted in 3/35 and low C4 in 18/35. Of 12 patients with a positive ASST, 7 had low complement levels, and 12/23 with a negative ASST had low complement levels. Patients with a positive ASST had a median C3 of 1.24 g/L (range 0.35–1.51) compared with a median of 1.25 g/L in those with a negative ASST ( P  = 0.36), and a median C4 of 0.20 g/L (range 0.185–0.452) in those with a positive ASST compared with 0.18 g/L in those with a negative ASST ( P  = 0.88).
Conclusions.  We conclude that both a reduction in C4 and positive ASST are common in CIU and although these immunological abnormalities often coexist, there is no clear relationship between them. Other components of the complement system may be worth exploring.     

Investigation of contact allergy to dental metals in 206 patients

Background:  Contact allergy to dental materials is poorly understood; clinical manifestations are heterogeneous.
Objective:  To analyse positive patch test reactions to metals (as their alloys or salts) used in dentistry together with clinical symptoms and possible relevance to dental fillings.
Methods:  We retrospectively analysed 206 patients who underwent patch testing with metals used in dentistry because of suspected contact allergy to them.
Results:  Twenty-eight of 206 patients had positive patch test reactions to metals used in dentistry. The number of positive patch test reactions was highest for gold sodium thiosulfate, palladium chloride, and nickel sulfate ( n  = 10, respectively), followed by amalgam, ammoniated mercury, and cobalt chloride ( n  = 4, respectively) and amalgam-mixed metals (including copper, tin, zinc, and silicon), and ammonium tetrachloroplatinate ( n  = 1). Only 14 (7%) of 206 patients had a clinically relevant contact allergy with conditions of the oral mucosa ( n  = 7 with lichen planus and n  = 7 with stomatitis) and positive patch test reactions to dental metals containing the suspected allergen. Improvement of symptoms was assessed in one patient with amalgam contact allergy 2 weeks after removal of dental fillings.
Conclusions:  Clinically relevant contact allergies to dental metals are infrequent. Gold sodium thiosulfate and palladium chloride presented the most frequent contact allergens.