Evaluation of role of Candida in patients with chronic paronychia.

BACKGROUND: Chronic paronychia, earlier considered to be an infection due to Candida, is currently being considered as a dermatitis of the nail fold. Irritant, allergic and protein contact dermatitis are the suggested major pathogenic mechanisms. Hypersensitivity to Candida is more likely to be the etiology, rather than the infection itself. AIMS: To assess the clinico-etiological profiles of patients with chronic paronychia and to determine the role of contact sensitization and hypersensitivity to Candida. METHODS: All consecutive patients of chronic paronychia attending the dermatology outpatient department (OPD) were assessed for risk factors, number of nails affected, clinical presentation and presence of fungus, patch tested for contact allergy and prick tested for hypersensitivity to Candida allergen. RESULTS: A total of 80 patients of chronic paronychia were recruited into our study. There was female preponderance (66 patients, 82.5%), with the most common group affected being housewives (47 patients, 58.8%). Frequent washing of hands (64 patients, 80%) was the most common risk factor. Fungal culture was positive in 56.1% (41 patients), the predominant species cultured was Candida albicans (15 patients, 36.5%). Patch testing with Indian standard series was positive in 27.1% patients (19 out of 70 patients tested), with nickel being the most common allergen. Prick test with Candida allergen was positive in 47.6% patients (31 out of 65 patients tested). LIMITATIONS: Prick test and patch test provide indirect evidence of hypersensitivity, with inherent limitations. CONCLUSION: Our study shows that chronic paronychia is probably a form of hand dermatitis associated with prolonged wet work, and that there is a higher incidence of contact sensitization and Candida hypersensitivity in these patients.

Parthenium dermatitis in India: past, present and future.

Parthenium dermatitis is an immuno-inflammatory disease caused by Parthenium hysterophorus and is the commonest cause of plant dermatitis in India. It is caused by airborne dry and friable plant particles including trichomes, and the most important allergens responsible for allergic contact dermatitis are sesquiterpene lactones. The combined type IV and type I hypersensitivity to parthenium has been recently postulated. In sensitized individuals, it can cause a spectrum of clinical patterns, such as classical airborne pattern, chronic actinic dermatitis-like presentation, mixed pattern dermatitis, exfoliative dermatitis, widespread dermatitis, and other rare patterns. There is definite trend towards change from airborne pattern to chronic actinic pattern in natural history of parthenium dermatitis. Contact sensitivity to parthenium is everlasting, and hence the disease runs a chronic course with exacerbation during summers. Patch testing with acetone or aqueous plant extract is the simplest way of confirming parthenium contact allergy. Management includes avoiding contact with allergen, managing dermatitis with topical corticosteroids/tacrolimus, and other immunosupressives like azathioprine. In future, we expect parthenium dermatitis to become less prevalent due to rapid urbanization and possible development of new biological methods to eradicate the parthenium. Genetic factors associated with susceptibility to parthenium dermatitis need to be studied.

Occurrence of plant sensitivity among patients of photodermatoses: a control-matched study of 156 cases from New Delhi.

BACKGROUND: Photodermatitis is an abnormal response to ultraviolet radiation (UVR). The photoallergic contact dermatitis caused by plant allergens is a serious cause of morbidity in India. Airborne contact dermatitis is the classical presentation of plant-induced dermatosis, which may become difficult to differentiate from chronic actinic dermatitis in chronic cases. The rapid growth of parthenium weed in India and its ill effects on the population make it important to detect all cases of parthenium sensitivity, which in some cases might simulate photodermatitis. AIMS: This study aims to detect the occurrence of plant sensitivity and photosensitivity in idiopathic-acquired photodermatoses, airborne contact dermatitis and general population taken as controls. METHODS: One hundred and fifty six consecutive patients suffering from polymorphic light eruption (PMLE), chronic actinic dermatitis (CAD) and airborne contact dermatitis (ABCD) were enrolled in the study over a period of three years (June 2004 to May 2007). An equal number of age and sex matched healthy subjects were enrolled in the study as controls. All the patients were subjected to detailed history taking, clinical examination and histopathological examination for diagnosis. Patch and photopatch testing were perfomed in all the patients and healthy controls for detection of allergic and photoallergic reactions to parthenium, xanthium and chrysanthemum plant antigens and control antigens. RESULTS: Out of 156 patients enrolled in the study, 78 (50%) had CAD, 67 (42.9%) had PMLE and 11 (7.05%) had ABCD. The occurrence of parthenium/xanthium allergy and photoallergy, either to parthenium or both was most commonly found in ABCD (72.7%), followed by CAD (32%). In PMLE 4.5% cases showed photoallergy. Only 1.9% in the control group showed sensitivity to parthenium and xanthium. CONCLUSION: This study indicates that parthenium (and possibly xanthium) may act as important environmental factors in the initiation and perpetuation of not only ABCD but of CAD as well. Photoexacerbation to UVA at positive parthenium/xanthium sensitivity sites in ABCD and CAD indicates that ABCD with photosensitivity to compositae can lead to CAD.

Type I hypersensitivity to Parthenium hysterophorus in patients with parthenium dermatitis.

BACKGROUND: Parthenium dermatitis is a major problem in urban and rural India. Patients with severe allergic rhinitis due to exposure to pollens of parthenium are reported to have parthenium specific IgE and IgG antibodies. Parthenium induces contact dermatitis by Type IV hypersensitivity and allergic rhinitis by Type-I hypersensitivity. AIMS: The study was undertaken to detect Type-I and Type-IV hypersensitivity amongst patients with parthenium dermatitis. METHODS: Fourteen patients with clinical features of parthenium dermatitis who patch tested positive to parthenium were included in the study. Patch testing was done by standard method and results interpreted as recommended by the ICDRG. Serum IgE was determined by chemiluminescence immuno assay system (CLIA). Prick testing was performed and interpreted by standard method. RESULTS: Twelve out of the 14 patients included, showed a positive prick test. Serum IgE was elevated in all patients to varying degrees (mean IgE-1279.9 IU/ml; N--up to 100 IU/ml). CONCLUSION: The positive patch test, prick test and elevated serum IgE suggest that both Type-I and Type-IV hypersensitivity may play a role in the induction and perpetuation of parthenium dermatitis in most patients. To date, delayed hypersensitivity was thought to be solely responsible for parthenium dermatitis. This study suggests that a combined type-I and type IV hypersensitivity mechanisms may be operational.

Centella asiatica (Indian pennywort), an effective therapeutic but a weak sensitizer.

The sensitizing capacity of Centella asiatica (raw extract) and its triterpenic constituents asiaticoside, asiatic acid and madecassic acid has been studied in guinea pigs. The extract itself as well as the 3 acids were found to be very weak sensitizers. Centella asiatica extract is used effectively in the treatment of keloids, leg ulcers, phlebitis, slow-healing wounds, leprosy, surgical lesions, striae distensae and cellulitis. Although applied frequently to damaged skin, the risk of acquiring contact sensitivity to this plant or its constituents is low.