Contact Dermatitis of the Vulva

BACKGROUND AND OBJECTIVESContact allergy is associated with a significant morbidity all over the world. This study was performed to investigate the pattern of sensitization by contact allergens in the local population.DESIGN AND SETTINGRetrospective study to investigate patch test reactivity among patients with clinical diagnosis of contact dermatitis who were referred to the allergy clinic at the King Khalid University Hospital, Riyadh, between April 2008 and March 2010.PATIENTS AND METHODSOf the 196 patients referred to the allergy clinic over the 2-year period, 91 (46.4%) patients reacted to one or more patch test allergens, and these patients were included in this study. The study group included 82 (91.1%) of Saudi nationality and 9 (8.9%) patients of other nationalities. The patch test was performed using the T.R.U.E TEST, containing 24 allergens/allergen mixes.RESULTSOf the 91 cases who reacted positively to one or more allergens, 67 (73.6%) were females with a mean age of 37 (8.3 years) and 24 (26.4%) were males with a mean age of 34 (11.6 years). Thirty-three (36.2%) patients reacted to nickel sulfate, 14 (15.3%) to p-phenylenediamine, 13 (14.2%) to p-tert-butylphenol-formaldehyde resin, 13 (14.2%) to thimerosal, and 9 (9.8%) to colophony. Reactivity against the rest of the allergens was not remarkable. A significantly higher percentage of females reacted to nickel sulfate (84.8% vs 15.2% in males; P=.0001), p-tert-butylphenol-formaldehyde resin (92.3% vs 7.7%; P=.0001), and thimerosal (76.9% vs 23.1%; P=.03).CONCLUSIONSPatch test reactivity to nickel sulfate was high. The pattern of contact allergy observed in this study indicates the need for large-scale investigations to identify local allergens responsible for contact allergy and for formulation of policies directed towards avoidance of exposure.

Results of Evaluating Health Care Workers With Prick and Patch Testing

Epidemiological survey of contact dermatitis in Italy (1984–1993) by GIRDCA (Gruppo Italiano Ricerca Dermatiti da Contatto e Ambientali)

Our understanding of the complex genetic susceptibility to occupational contact dermatitis (OCD) is still in the early stage. The search for candidate susceptibility genes focused mainly on proteins involved in skin barrier and immune response which have a key role in both irritant and allergic contact dermatitis (respectively, ICD and ACD). Furthermore, for ACD genetic variations in enzymes involved in metabolism of contact allergens have been investigated. Among skin barrier genes, lossof- function mutations in the filaggrin gene (FLG) have been identified as a risk factor for irritant contact dermatitis (ICD); the riskmodifying effect of FLG mutations was stronger in the presence of atopic dermatitis. In ACD, the impact of FLG mutations was allergen specific and dependent on the outcome measure and the exposure pattern. Several studies reported association of genetic polymorphisms in the metabolizing enzymes N-acetyltransferase and glutathione S-transferase with ACD; however the results are so far inconclusive. Among inflammatory genes, there appears to be an effect of TNFgene polymorphisms on susceptibility to both irritant and allergic CD, suggesting that they share some common pathways. At present, the predictive value of genetic markers for the appearance of OCD is too low for reasonable identification of susceptible individuals in occupational health practice. Further well-designed studies in larger cohorts with a well-defined disease phenotype and external exposure in the control as well as in the case group are needed to confirm and extend our knowledge of the impact of genetic variations on the susceptibility to OCD.

34 - Contact Dermatitis

The diagnosis of combined allergic and irritant contact dermatitis is an accepted subdiagnosis for hand dermatitis, and it is often considered in a patient with contact dermatitis, a positive and relevant patch test result, and wet work exposure. We therefore hypothesize that it is arbitrary for wet work exposure to be taken into consideration in a patient with newly diagnosed relevant contact allergy. Furthermore, an overestimation of the diagnosis will probably occur if the criteria for wet work exposure are applied correctly, as many occupations have an element of wet work. To find the statistically expected number of combined allergic and irritant contact dermatitis cases in 1000 patients, and to evaluate the diagnostic criteria for the diagnosis. One thousand consecutive patients with occupational contact dermatitis from a hospital unit in Denmark were assessed. The expected number of cases with the diagnosis of combined allergic and irritant contact dermatitis was 0.33%, as compared with the observed number of 6.4%. Females occupied in wet occupations were often diagnosed with combined allergic and irritant contact dermatitis (p < 0.005). The diagnosis of combined allergic and irritant contact dermatitis should be used critically to avoid misclassification, and possible criteria for the diagnosis are proposed.

Contact dermatitis is a common condition that can be categorized as irritant dermatitis and allergic contact dermatitis. Although each of these conditions may have a similar presentation, allergic contact dermatitis is immunologically mediated, whereas irritant contact dermatitis is not. Contact dermatitis can be acute, subacute, or chronic, and each of these phases may progress into the next. Almost any substance may induce a cutaneous reaction, depending on its concentration, the duration of contact, and the condition of the contacted skin. It is estimated that there are more than 6 million chemicals in the environment; approximately 3000 are potential sensitizers. A careful history may identify the responsible agent. If the contactant is identified and eliminated, the contact dermatitis can be a self-limited, mild condition. H the exposure is not discontinued, a cycle of itching, scratching, and skin disruption occurs, which leads to chronic changes in the skin. The history of presentation, including occupational exposures, and distribution of the rash are important in identifying the offending agent. More severe cases may require more extensive evaluation, possibly including patch testing, to determine the offending agent. This article reviews treatment, including antihistamines, topical and oral steroids, physical measures such as cold water compresses, and the treatment of secondary infection.

Dieffenbachia Schott, commonly known as dumb cane, is a popular ornamental house plant renowned for its striking foliage. The plant’s sap contains calcium oxalate crystals, which can cause irritant or allergic contact dermatitis upon direct exposure. While allergic reactions to Dieffenbachia are rare (eye symptoms and severe irritant skin allergies), the plant’s widespread domestic presence poses a significant risk, which we discuss in our case below. A 68-year-old woman who was an avid gardener was rearranging her long-standing indoor plant. During a routine tidying session, she removed two leaves barehanded, noting sap exposure on her fingers. They began to tingle. She remembers wiping the skin but not washing it. The following morning there were multiple painful blisters on the fingers between the web spaces of her right hand. Her medical history included an irritant contact allergy to hyacinth bulbs. She was given antihistamines and mild topical corticosteroids. However, symptoms worsened with larger blisters developing. Examination revealed blistering and erosions between the web spaces with an annular erythematous edge. She felt mildly unwell and a fever brewing. The C-reactive protein was mildly elevated at 12 mg L−1. The clinical impression was of an irritant contact dermatitis due to Dieffenbachia sap. Management involved oral flucloxacillin for 1 week, topical betamethasone dipropionate with clotrimazole applied twice daily for 2 weeks, potassium permanganate soaks, Dermol 500 as a soap substitute, and white soft paraffin as a moisturizer. At follow-up, the patient showed complete resolution of symptoms and significant recovery of the affected skin. Indoor plants are thought to be safe. However, this case underscores the rare presentation of a likely progressing irritant contact dermatitis from Dieffenbachia sap. We know this can affect eyesight if the sap comes in contact with the mucosa. We felt an irritant contact dermatitis was most pertinent given the severity and acute nature of the eruption and thus did not patch test her. The history of hyacinth bulb allergy may have predisposed her to a lower threshold for a reaction. We present this case for wider acknowledgement of plant eruptions and suggest that gardening gloves are a useful adjunct for handling outdoor as well as indoor plants.

Amputees who use prosthetic devices are particularly vulnerable to contact dermatitis due to factors such as moisture, friction, and prolonged exposure to prosthetic materials. Distinguishing between allergic contact dermatitis (ACD) and irritant contact dermatitis (ICD) can be difficult, as the symptoms often overlap; therefore, careful evaluation of patient history, clinical features, and diagnostic tests is required. Allergic contact dermatitis in amputees frequently is triggered by exposure to materials such as rubber, metal, and adhesives, whereas ICD often is caused by friction and moisture accumulation within the prosthetic socket. Effective management involves differentiating between ACD and ICD and subsequently using patch testing to identify specific allergens in cases of ACD. Treatment of ICD focuses on minimizing mechanical irritation, controlling moisture, and maintaining skin barrier function. Newer therapies, including botulinum toxin injections and laser hair removal, offer additional options for managing sweat-induced skin irritation in prosthetic users. A comprehensive understanding of the causes and presentation of both ACD and ICD is essential for improving prevention, diagnosis, and treatment strategies in this population.

Reflectance confocal microscopy may differentiate acute allergic and irritant contact dermatitis in vivo

Irritant contact dermatitis (ICD) is characterized by direct injury to the epidermal cells, activating the innate immune response. Allergic contact dermatitis (ACD), in contrast, is delineated by a delayed hypersensitivity reaction of type IV. Despite the distinct etiopathogenic mechanisms under-pinning each condition, the differentiation between them presents a significant diagnostic challenge. This study aimed to determine whether a combination of clinical evaluation and noninvasive measurements-encompassing oxidative stress, erythema, hydration, melanin content, transepidermal water loss (TEWL), hemoglobin concentration, and skin texture and volume-could distinguish ICD from ACD. Two cohorts, each comprising 21 patients, were evaluated: one diagnosed with ICD and the other with ACD. All participants underwent biophysical and clinical assessments, along with Antera® 3D evaluations. Tape strips were utilized for skin sampling, and oxidative stress levels were measured via fluorescence assessments. ICD prompted an almost immediate inflammatory reaction (peaking at 24 hours), whereas ACD incited a delayed response (72 hours). Noninvasive evaluated parameters such as hemoglobin concentration, skin texture and volume, melanin content, erythema, and TEWL showed significant differences between the ICD and ACD cohorts (P < 0.05). The allergens amcinonide, nickel sulphate, cobalt chloride, budesonide, PPD, and thiuram mix were found to induce elevated levels of oxidative stress. The evaluation of patients with noninvasive parameters, including transepidermal water loss (TEWL), hemoglobin concentration, and skin texture and volume, could markedly aid in distinguishing irritant contact dermatitis from allergic contact dermatitis (ACD). Nevertheless, the study was constrained by a limited sample size.

Occupational skin disease is one of the most common occupational diseases. The hand is the most frequent site of involvement in occupational skin disease. We interviewed and examined patients seen in the Contact Dermatitis Clinic of the National Taiwan University Medical Center, a tertiary referral center in Taipei City. For patients suspected of having allergic skin diseases, patch testing was carried out using the European standard series and suspected allergens. Occupational hand dermatitis (OHD) was diagnosed according to medical history, work exposure, physical examination, and patch test findings. 36% of patients seen were diagnosed as having OHD. Electronics, hairdressing, medical, chemical, and construction were the most important industries causing OHD. In the 164 patients with OHD, 58.5% had irritant contact dermatitis (ICD) and 41.5% allergic contact dermatitis (ACD). Dorsal fingers, nail folds, and dorsal hands were most frequently involved in patients with ACD; dorsal fingers, volar fingers and fingertips were most frequently involved in those with ICD. Using logistic regression analysis, we were able to identify the most important clinical presentations that predicted the types of OHD, ACD versus ICD. Patients with atopic history and palm involvement were more likely to have ICD, and those with nail fold involvement more likely to have ACD. In patients with ACD, the most important allergens were dichromate, nickel, cobalt, fragrance mix, epoxy resin, thiuram mix, and p-phenylenediamine. In this study, we identified the important industries and causal agents for OHD. Future preventive measures focused on these industries and agents to reduce OHD will be warranted.

COMPARISON OF ALLERGIC AND IRRITANT CONTACT DERMATITIS

We have investigated 115 patients presenting with dermatoses, who worked with cutting oils. The study period was from 1986 to 1987. There were 111 men and 4 women, with ages ranging from 16 to 66 years (mean 42 ± 14.3 years). The final diagnoses were as follows: 28 patients had endogenous hand eczema and irritant contact dermatitis (ICD); 22 allergic contact dermatitis (ACD) and ICD; 21 ICD alone; 19 ACD alone; 12 endogenous hand eczema; 6 other (non-eczematous) conditions; 4 ACD, ICD and endogenous hand eczema; and 3 ACD and endogenous hand eczema. Formaldehyde-releasing biocides were the commonest cause of allergic reactions in the cutting oil series. Reactions were also seen to colophony, formaldehyde, nickel, rubber, dichromate and epoxy resin in the International Contact Dermatitis Research Group (ICDRG) standard series. As 42% of the patients had relevant positive patch tests, patch testing remains an essential investigation in the management of cutting oil dermatitis.

There is increasing evidence that reactive oxygen species play an important role in the development of both irritant and allergic contact dermatitis. To assess the potential of topical antioxidants to prevent the development of experimentally induced irritant contact dermatitis. We evaluated the effect of a cream containing a combination of antioxidants on sodium lauryl sulfate-induced irritant contact dermatitis in the repetitive washing test. As readout parameters for skin barrier function and cutaneous inflammation stratum corneum hydration, cutaneous blood flow and transepidermal water loss were assessed in 25 volunteers with bioengineering methods. In comparison with the cream base and a frequently used barrier cream, the antioxidant cream had high radical scavenging activity and effectively protected the skin from chemical-induced irritation. The superiority of the cream with antioxidants to the cream base suggests that reactive oxygen species, at least in part, play a role in the development of irritant contact dermatitis.