Common Allergens in Foot Dermatitis attributable to Footwear

Swarnalakshimi, S (2015) Common Allergens in Foot Dermatitis attributable to Footwear. Masters thesis, PSG Institute of Medical Sciences and Research, Coimbatore.


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INTRODUCTION: Contact dermatitis is classified into two groups: irritant contact dermatitis and allergic contact dermatitis. Irritant contact dermatitis is more frequent and occurs in anyone exposed to an irritant for a sufficient duration and concentration. In contrast allergic contact dermatitis is a T cell mediated immunological reaction, occurs only when the skin in previously sensitized person is reexposed to that allergen. The etiology can be related to several factors acting singly or in combination. Contact eczema may also be characterized into endogenous conditions like atopic or exogenous causes such as contact dermatitis. (both allergic and irritant contact dermatitis). Foot dermatitis is one of the common problems seen by the dermatologist. It causes discomfort and embarrasment to the patients. Although the majority of the Indian population used to walk barefoot, the trend has changed with more adopting some protective footwear. As a result increasing numbers of dermatitis attributable to footwear present to the dermatologist. There are 4 major factors which influence footwear dermatitis, namely allergy, atopy, friction, and occlusion. The clinical presentation of foot wear dermatitis has varied presentation from region to region and with time .The prevalence in South India is 11.7% as compared to 3-6% from abroad3,4,5 Leather, rubber & adhesives have been reported to be the most common allergen. Most of the incriminating allergens can be identified by patch testing. Irritant reactions have to be differentiated and usually fade by the second reading. The diagnosis of contact allergens by patch testing gives the clinician a distinct advantage in the subsequent management of the patient & improves the prognosis by avoidance of the possible sources of the allergen. In the market a variety of footwear is available from different manufacturers who do not furnish a list of the constituents. Incorporating the list of constituents of footwear would help sensitized patients to select those without the culprit allergens. AIMS & OBJECTIVES: 1. To identify the common allergens in foot dermatitis attributable to footwear. 2. To prepare handouts with information on the possible household and occupational sources of the incriminating allergens other than those in the Indian Standard Series (ISS). MATERIALS AND METHODS: This study was conducted over the period of 16 months from April 2013 to August 2014 in the department of Dermatology PSGIMSR Coimbatore Tamilnadu. During this period total number of 40 patients with foot dermatitis attending the outpatient departments were included in this study. An informed consent was taken from all the patients. Patients details were recorded in the proforma (age, occupation, duration of illness, site of initial lesion, extent of involvement, type of footwear, seasonal variations, association with atopy). In patients showing extensive scaling/suspecting fungal infections KOH. Skin scraping was carried out in addition to patch testing. In patients with family history or personal history of atopy serum IgE was done. In case of purulent discharge from the lesions pus culture sensitivity was sent to rule out concomitant bacterial infections. Past treatment history (topical/systemic) was also recorded. The Clinical signs and symptoms like itching with oozing, scaling, pustules, erythema, vesicles, purpura, hyperpigmentation, depigmentation, lichenification were recorded. Area of involvement was recorded as symmetrical/ asymmetrical lesions, dorsum of the foot, dorsum of the toe, plantar surface, heel and sparing of instep/flexures. Inclusion criteria: Investigation of patients with eczematous eruptions mainly over the foot. Exclusion criteria: 1. pregnant and lactating mother, 2. patient with exfoliative dermatitis, 3. patients on systemic immunosuppressants and high dose oral steroids. CONCLUSIONS: Foot eczema is one among the many common dermatological disorders that is seen in dermatology outpatient departments. The most common morphological pattern was dry scaly plaque. Patch testing has played an important role in identifying patients with footwear dermatitis as all patch positive (30 out of 40) patients showed sensitivity to one or more of the allergens in the footwear series. Instep involvement, an uncommon presentation in footwear dermatitis, was seen in a single patch test negative patient who was an atopic with raised IgE. The 3 common allergens include nickel, chromate and NN DPG. Although nickel and chromate have remained the commonest allergens in the past, the rubber allergen NN DPG has emerged as a common sensitizer. Earlier reports have detected MBT to be the common allergen in rubber. This could be related to the increasing use of NN Diphenylguanidine in the processing of rubber. Sometimes patch testing with foot wear series may yield negative results; in this situation it would be advisable to include pieces of patients own footwear for testing. Sometimes the specific needs to be released from the footwear prior to testing by sophisticated processes like ultrasonication. HPLC (high pressure liquid chromatography) may isolate the individual components of the particular footwear and patch testing with these may sometimes yield a positive result. This study has enabled the compilation of data related to household and occupational exposure of the allergens in the footwear series in the form of pamphlets for distribution to the patients both in English and Tamil. This would help to educate patients on allergen avoidance for freedom from disease.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Common Allergens ; Foot Dermatitis attributable ; Footwear.
Subjects: MEDICAL > Dermatology Venereology and Leprosy
Depositing User: Punitha K
Date Deposited: 05 May 2018 10:18
Last Modified: 05 May 2018 10:18

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