Atopy Associated With Positive Patch Test and Possible Allergic Contact Dermatitis

BACKGROUND

Atopy is a genetic predisposition to the development of allergic reactions and the increased production of immunoglobulin E (IgE) upon exposure to environmental antigens. Clinical manifestations of atopy include asthma, atopic dermatitis (AD), and allergic rhinoconjunctivitis (ARC).

OBJECTIVE

To determine if cutaneous delayed hypersensitivity reactions (CDHRs) as assessed by patch testing are higher among patients with a history of atopy and with a familial predisposition to atopy.

METHODS

For this study, we reviewed the patch test database of the UBC Contact Dermatitis Clinic over a 4-year time span. A personal history of asthma, AD, and ARC was recorded. In addition, a family history was obtained and manifestations of atopy in family members were noted.

RESULTS

A total of 1515 patients were included in this study. Our data show that the odds ratio (OR) of a positive patch test with a personal history of atopy was 1.39, while the OR of a positive patch test with a family history of atopy was 1.69. Conversely, a personal history of respiratory atopy did not significantly affect the probability of a positive patch test, with an OR of 1.03.

CONCLUSION

We conclude from our study that patients with a personal or family history of atopy have an increased risk of allergic contact dermatitis (ACD). These results provide further evidence for the link between atopy and ACD and suggest that children of atopic parents should avoid potential contact allergens and would likely benefit from prophylactic emollient use.

Methylisothiazolinone Contact Allergy Prevalence in Western Canada: Increased Detection With 2000 ppm Patch Test Allergen

Background:

Contact allergy to methylisothiazolinone (MI) or to the combination of methylchloroisothiazolinone and MI (MCI/MI) is an important and increasing cause of allergic contact dermatitis, with prevalence rates higher than 10% in some centers.

Objectives:

The objective of this retrospective chart review is to provide a western Canadian perspective on whether the positive patch testing rate to MCI/MI or MI increased during the testing period of 2008 to 2015 and whether the addition of MI at 2000 ppm resulted in increased detection.

Methods:

We conducted a retrospective chart review of patients who tested positive (n = 104) of 2177 total patients who were patch tested for MCI/MI or MI at a community dermatology clinic in Vancouver, British Columbia, Canada, from January 2008 through April 2015.

Results:

One hundred and four patients had positive patch testing results for MCI/MI, MI, or both. Positive results increased over the study period, with the highest prevalence in 2015 at 9.41% for MCI/MI, 12.94% for MI, and 15.29% for either. When testing for MI at 2000 ppm was introduced in 2013, the initial positive patch testing prevalence was 6.6%, followed by 10.1% in 2014, and 12.9% in 2015.

Conclusions:

We demonstrate an increasing prevalence of MCI/MI and MI allergy between 2008 and 2015, with the highest prevalence of 15.29% in 2015 for MCI/MI and/or MI allergy. The addition of MI 2000 ppm greatly increased the positive patch testing yield for MI. Our results support the importance of continued efforts to monitor and regulate these preservatives.

Early Detection of Skin Cancer by Family Physicians: A Pilot Project

Background:

Malignant melanoma is rising quickly in incidence and mortality rates. Family physicians (FPs) have been reported to lack confidence in diagnosing skin cancers. Objective: The aim of this study was to determine whether an educational intervention can improve FPs' abilities to diagnose skin cancers.

Methods:

The design was a prospective, randomized trial which included a skin cancer questionnaire, a video intervention, and a skin biopsy review.

Results:

Pre-intervention, FPs answered 57% of the questions correctly on the skin cancer questionnaire. Post-intervention, the video intervention group scored higher than did the control group. The video intervention group removed 10% fewer benign lesions and almost 3 times more malignant lesions compared with their pre-intervention biopsy rate. No findings were statistically significant.

Conclusion:

An educational intervention may improve FPs' knowledge and diagnosis of skin cancer. Our results may guide future studies with larger sample sizes in developing a skin cancer continuing medical education (CME) course for FPs.

Friction-induced pagetoid dyskeratosis

BACKGROUND

Pagetoid dyskeratosis (PD) is characterized by pale cells within the epidermis resembling those of Paget disease. These cells have been seen as an incidental finding in a variety of benign papules most commonly located in intertriginous areas. The lesion is considered a reactive process in which a small proportion of the normal population of keratinocytes is altered. Among the triggers for this lesion, friction has been suggested; however, a direct cause-and-effect relationship has not yet been reported.

RESULTS

We confirmed the relationship between PD and friction in a biopsy taken from a 19-year-old woman who presented with clinical features indicating exogenously induced bullae and erosions and consented to a biopsy of a lesion immediately after its induction, demonstrating combined features of PD and friction bulla.

The health controversies of parabens

Parabens are preservatives used in a variety of personal care, cosmetic, pharmaceutical and food products. Studies have confirmed the ubiquitous presence of parabens, with levels detected in wastewater, rivers, soil and house dust. Parabens have also been detected in human tissues and bodily fluids, but it is the discovery of these chemical compounds in the breast tissue of patients with breast cancer that has raised public concern over their use. It is hypothesized that the estrogenic properties of parabens may play a role in breast cancer development. However, studies investigating the health effects of parabens are conflicting. At this point, there is an insufficient amount of data suggesting serious consequences from paraben use and exposure to warrant drastic avoidance measures or government regulations.

HIV dermatology in Canada: cutaneous disease burden and demographic characteristics of a specialized urban practice

BACKGROUND

The introduction of antiretroviral therapies has changed the pattern of cutaneous disease in individuals infected with human immunodeficiency virus (HIV).

OBJECTIVE

To assess demographic characteristics, severity of immunosuppression, and frequency of dermatologic disorders in patients presenting to a Canadian specialized HIV dermatology practice.

METHODS

A cross-sectional study was performed of 183 consecutive outpatient and inpatient consultations to a single HIV dermatology practice from January 2007 to December 2008.

RESULTS

One hundred sixty-three (88%) patients were male, with an average age of 45. Forty-six patients were not on antiretroviral therapy. Verruca was the most common diagnosis, seen in 29 patients, followed by dermatophyte infection, seen in 27. Patients with a low CD4 count (p  =  .0001) and a high viral load (p  =  .0043) were more likely to present with an HIV-specific dermatosis.

CONCLUSION

Cutaneous infections were the most common diagnoses in this cross section. Classic HIV dermatoses were seen more frequently in those with more advanced disease owing to HIV infection.

Allergic contact dermatitis to preservatives and fragrances in cosmetics

Cosmetics are an important cause of allergic contact dermatitis (ACD). Fragrances and preservatives are the two most clinically relevant allergens found in cosmetic products. Patch testing remains the gold standard for identification of causative allergens. Common cosmetic allergens are reviewed. Practical methods of allergen avoidance are also discussed.

Psoriasis and pustular dermatitis triggered by TNF-{alpha} inhibitors in patients with rheumatologic conditions

BACKGROUND

New onset or worsening of psoriasis has been reported in patients treated with tumor necrosis factor alpha (TNF-alpha) inhibitors for a variety of rheumatologic conditions. There is mounting evidence that a key innate immune pathway for triggering common human autoimmune disease, including psoriasis, involves plasmacytoid dendritic cell precursors (PDCs) and type 1 interferon (IFN) production. We present herein a case series with clinical and histopathologic evidence of psoriasis in patients with rheumatologic disease treated with TNF-alpha inhibitors. We propose that the cross regulation between TNF-alpha and IFN may have a role in the pathogenesis of this reaction.

OBSERVATIONS

We observed new-onset psoriasis (n = 13) or severe exacerbation of psoriasis (n = 2) in 15 patients with a variety of rheumatologic conditions-rheumatoid arthritis (n = 13), psoriatic arthritis (n = 1), and seronegative arthritis (n = 1)-during treatment with etanercept (n = 6), infliximab (n = 5), and adalimumab (n = 4). Immunohistochemical staining of skin biopsy specimens for myxovirus-resistance protein A (MxA, a surrogate marker for lesional type 1 IFN activity) showed increased staining in TNF-alpha inhibitor-induced psoriasis compared with psoriasis vulgaris.

CONCLUSIONS

New onset or severe exacerbation of psoriasis is a rare complication of TNF-alpha inhibitor therapy. The finding of increased production of IFN-alpha in TNF-alpha inhibitor-induced psoriasis is a possible pathophysiologic explanation for this reaction.

Early detection of skin cancer by family physicians: a pilot project

BACKGROUND

Malignant melanoma is rising quickly in incidence and mortality rates. Family physicians (FPs) have been reported to lack confidence in diagnosing skin cancers.

OBJECTIVE

The aim of this study was to determine whether an educational intervention can improve FPs' abilities to diagnose skin cancers.

METHODS

The design was a prospective, randomized trial which included a skin cancer questionnaire, a video intervention, and a skin biopsy review.

RESULTS

Pre-intervention, FPs answered 57% of the questions correctly on the skin cancer questionnaire. Post-intervention, the video intervention group scored higher than did the control group. The video intervention group removed 10% fewer benign lesions and almost 3 times more malignant lesions compared with their pre-intervention biopsy rate. No findings were statistically significant.

CONCLUSION

An educational intervention may improve FPs' knowledge and diagnosis of skin cancer. Our results may guide future studies with larger sample sizes in developing a skin cancer continuing medical education (CME) course for FPs.