Clinicoepidemiological and Patch Test Profile of Patients Attending the Contact Dermatitis Clinic of a Tertiary Care Hospital in North India: A 7-Year Retrospective Study

Evaluation of vitamin D receptor gene polymorphisms (ApaI and TaqI) as risk factors of vitiligo and predictors of response to narrowband UVB phototherapy

Vitiligo is acquired depigmentation due to multiple factors. Vitamin D in skin, through its receptors (VDR), regulates cell growth, differentiation, immune response and exerts both stimulatory and protective effects on melanocytes. The gene sequence encoding VDR has polymorphic forms such as ApaI and TaqI that may affect vitamin D actions. Narrowband ultraviolet B (NB-UVB) phototherapy became the mainstay of vitiligo treatment because of its efficacy and little side effects. The current work aimed at evaluating the possible association between VDR gene polymorphisms (TaqI and ApaI) and susceptibility of vitiligo and if they could be predictors of response to NB-UVB phototherapy in Egyptian vitiligo patients. 100 vitiligo patients indicated for NB-UVB phototherapy and 100 healthy age and sex matched controls were included. All participants were subjected to history taking, general and dermatological examinations, and VDR ApaI and TaqI gene polymorphisms analysis by PCR-RFLP. The patients received NB-UVB 3times per week for 6 months then revaluated. There was significant increase in Aa genotype of ApaI polymorphism in patients associated with significant increase in vitiligo activity. 66% of patient showed variable degrees of response to NB-UVB. The responders significantly had AA genotype of ApaI polymorphism. TaqI polymorphism showed nonsignificant effects on vitiligo susceptibility and response to NB-UVB. A allele of ApaI was significant independent predictor of NB-UVB phototherapy responders. VDR gene polymorphism (ApaI) may share in vitiligo pathogenesis and response to NB-UVB. Knowing the genetic background of the patient helps individualization of treatment to get better results.

Standard patch test results and clinical relevance: A cross-sectional study of 10-year retrospective experience

Background:

Allergic contact dermatitis (ACD) is a type IV hypersensitivity reaction, and The European Standard Series (ESS) Patch Test (PT) is widely used in determining the possible responsible allergens causing ACD. The dynamic nature of the industrial products, socioeconomic and environmental factors cause the frequency of common allergens to change over the years and among different regions.

Aims and Objectives:

This study aimed to retrospectively evaluate the results of ESS PT of our centre in the last decade, and determine the current spectrum of allergens and their clinical relevance.

Materials and Methods:

The data of patients who underwent ESS PT in our clinic between January 2010 and March 2020 were included in the study. The patient files were examined retrospectively. The clinical relevance was evaluated according to the COADEX system. Statistical analysis used: SPSS for Windows version 23.0 software program.

Results:

The data of 1037 patients [623 (60.1%) female, 414 (39.9%) male] were analysed. The mean age was 38.34 ± 14.55 years. The five most common allergens were nickel sulphate (23.1%), cobalt chloride (12%), potassium dichromate (9.5%), Fragrance mix II (7.3%) and balsam of Peru (5.7%). According to the COADEX coding system, current relevance was detected in 319 (49.3%) of 646 patients who had a positive reaction to any substance in the patch test.

Conclusion:

Our study showed that with increasing awareness in society, the tendency to avoid some well-known allergenic substances and consumer products causes changes in common allergens. These results prove the value of long-term surveillance of contact allergy.

Clinical, Occupational and Allergological Profile of 455 Patients with Occupational Contact Dermatitis: A 5-Year Study from a Tertiary Care Center of North India

Objectives:

To evaluate clinical and occupational profile and common allergens in patients with occupational contact dermatitis (OCD).

Materials and Methods:

The records of 455 (M:F 2:1) patients aged 18-85 years with allergic contact dermatitis were analyzed retrospectively. The diagnosis of OCD and patterns of dermatitis were defined by standard criteria. Indian standard series comprising 20 allergens and when suspected patient's own products were patch tested by Finn chamber method as per European Society of Contact Dermatitis guidelines and relevance of positive results was defined clinically.

Results:

Airborne contact dermatitis (27.7%), acral dermatitis (14.1%), hand dermatitis (12.9%), acrofacial dermatitis (12.7%), and facial dermatitis (10.5%) were the common patterns. Agriculturists (51.2%), homemakers (27.9%), office workers (24.6%), and construction workers (4.6%) comprised the majority. Positive patch test results in 58% cases were from parthenium (31.7%), p-paraphenylenediamine (PPD) (22.9%), nickel (16%), fragrance mix (11%), potassium dichromate (10.7%), cobalt (7.6%), and mercaptobenzothiazole (4.9%). Hair colorants, shoe chips, and shaving cream also produced relevant positive reactions. Parthenium, PPD, fragrance mix, and potassium dichromate in agriculturists; nickel, parthenium, PPD, fragrance mix, and potassium dichromate in women, and potassium dichromate and parthenium in construction workers elicited the most positive reactions. PPD and hair colorants elicited positive reaction mainly in office workers.

Conclusions:

The agriculturists, homemakers, and construction workers have OCD most frequently. Parthenium in farmers, potassium dichromate in construction workers, nickel in women, and PPD in office workers were the major contact allergens. The study is limited by its retrospective design, small number of patients, and limited number of patch test allergens.