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Changes in skin pigmentation in the elderly
Symposium
S20. Geriatric
proteins in the clinic, 25% presented with eczematous reactions, not explained by concomitant type-IV allergy or atopic hand eczema. Cases will be discussed. S19-3
The mechanism dermatitis
T. Bieber. Department
of protein
of Dermatology,
contact University
of Bonn,
Germany
Protein contact dermatitis (PCD) is a common disease, mostly occurring in the context of occupational activities, e.g. in foodhandlers or veterinary surgeons. Although clinically almost well defined, no clearcut pathophysiological mechanisms have been attributed so far to PCD. Several scenarios may be envisaged to explain the events underlying this peculiar skin disease. Such events may include immunological and/or non-immunological reactions. Among immunological reactions, IgE-mediated activation of dermal mast cells is the most likely to explain the acute/urticarial component of the rush but not the dermatitis aspect which may be explained by other mechanims involving a combination of immediate and delayed type hypersensitivity. Among non-immunological mechanisms, toxic or pseudo-allergic reactions may be relevant. Detailed dissection of the immunological and molecular events in this disease are required to (i) answer the question whether PCD is a form of contact urticaria and (ii) to develop specific therapeutical approaches.
s33
dermatology
S19-5
Atopy
patch test in adults
J. Ring, U. Dar-sow, M. Gfesser. Dept. Dermatology Allergology
Biederstein
Munich,
The atopy patch test (APT) is a procedure involving epicutaneous patch tests with allergens known to elicit IgE-mediated reactions and the evaluation of eczematous skin lesions. APT can be performed on normal uninvolved skin without artificial manipulations such as tape stripping or use of irritants. APT has been standardized regarding the use of vehicle and dose response relationships. Positive APT reactions were significantly more frequent in pati-ents with a typical air-exposed eczematous distri-bution pattern. Using evaporimetry to study trans-epidermal water loss, allergeninduced disturbance of epidermal barrier functions was found to be significantly more pronounced on APT reactions compared to classical contact allergy patch test sites in the same individual. It has been shown that with APT eczematous skin lesions can be elicited by skin contact with aeroallergens, at least in a subgroup of patients with AE, and thereby, that IgE-mediated allergy does play a role in the etiopatho-physiology of this disease.
s20. S20-2
Geriatric dermatology Changes
in skin pigmentation
J.-P. Ortonne. U3M INSERM, I S19 4 Systemic children
protein
Kristiina Turjanmaa. Department University
Hospital,
Tampere,
contact
dermatitis
of Dermatology,
in Tampere
Finland
Patch testing with aeroallergens has been found to be a useful model to study the inflammatory reaction in atopic eczema (AE). Recently, protein patch tests (PPT) with cow milk (CM) powder have been used in children with AE and/or gastrointestinal (GI) symptoms and were found to be more often positive in children with delayed-type reactions to CM challenge, whereas skin prick test- or RAST-positive children more often react immediately to challenge. The elimination-challenge procedure is the only relevant diagnostic test for food allergy/intolerance. The problem at present is that most children show multiple food sensitization, and extensive elimination diets are needed to get the skin or the GI tract symptomless for the challenge tests. Skin tests can be used to plan these diets, but prick tests and RAST are known to have low sensitivity and specificity in children with AE. Therefore, PPT seems to bring more information. Majamaa, Holm and Turjanmaa (unpublished) analyzed PPTs in 69 milk challenge-positive infants: 30 were milk powder PPTpositive and 27130 showed negative skin prick test or RAST to CM. Although the sensitivity and specificity of PPTs have not been extensively studied, they seem to give additional information for use in planning elimination diets before challenge. Speculatively, PPT with foods could be regarded as a method for diagnosing systemic protein contact dermatitis where the contact takes place in the GI tract, and antigen-specific T cells then selectively migrate to the skin causing AB in genetically predisposed persons.
and
Germany
Dermatologie,
Hepita
in the elderly
Facult6 de Mdecine, de L’Archet, Nice, France
Service
de
Chronological aging, as well as photoaging modifies the melanocyte system of the skin. In the epidermis and the hair, melanin pigment are good indicators of aging. Uneven pigmentation is one of the major aging features in gross morphology of the skin and is more marked in exposed skin, indicating that W-irradiation plays a major role in the induction of these modifications. Thus dyspigmentation is one of the main clinical features distinguishing photodamaged skin from inhinsicalIy aged skin. Despite the decreased melanocyte density, photoaged skin has irregular pigmentation and, frequently there is hypetpigmentation. This may be due to greater melanogenic activity of some chronically irradiated melanocytes. The most common pigmented lesions in sun-exposed skin include ephelides, actinic lentigo, sunbeds lentigines, pigmented solar keratoses and seborrhoeic keratoses, pigmented epithehomas and lengigo maligna. Lesions of erythromelanosis interfolIicuhuis are very often heavily pigmented. Exposure to W-radiation also seems to play a role in the manifestation of acquired naevi. The white spots in aged skin are usually stellate pseudoscam or idiopathic guttate hypomelanosis. Medical treatment of dyspigmentation of photoaged skin includes topical tretinoin and depigmenting agents, and to a lesser extent alpha-hydroxy-acids. Surgical procedures such as liquid nitrogen cryotherapy. chemexfoliation with tichloroacetic acid, phenol or alpha-hydroxy-acids, dermabrasion and laser resurfacing and surgical ablation with the recently developed pigment-specific lasers are also widely used. Last but not least, prevention should begin in early childhood and extend throughout life (limitation of mid day sun-exposure, WA and WB sunscreens, photoprotective clothing...).
S20. Geriatric
proteins in the clinic, 25% presented with eczematous reactions, not explained by concomitant type-IV allergy or atopic hand eczema. Cases will be discussed. S19-3
The mechanism dermatitis
T. Bieber. Department
of protein
of Dermatology,
contact University
of Bonn,
Germany
Protein contact dermatitis (PCD) is a common disease, mostly occurring in the context of occupational activities, e.g. in foodhandlers or veterinary surgeons. Although clinically almost well defined, no clearcut pathophysiological mechanisms have been attributed so far to PCD. Several scenarios may be envisaged to explain the events underlying this peculiar skin disease. Such events may include immunological and/or non-immunological reactions. Among immunological reactions, IgE-mediated activation of dermal mast cells is the most likely to explain the acute/urticarial component of the rush but not the dermatitis aspect which may be explained by other mechanims involving a combination of immediate and delayed type hypersensitivity. Among non-immunological mechanisms, toxic or pseudo-allergic reactions may be relevant. Detailed dissection of the immunological and molecular events in this disease are required to (i) answer the question whether PCD is a form of contact urticaria and (ii) to develop specific therapeutical approaches.
s33
dermatology
S19-5
Atopy
patch test in adults
J. Ring, U. Dar-sow, M. Gfesser. Dept. Dermatology Allergology
Biederstein
Munich,
The atopy patch test (APT) is a procedure involving epicutaneous patch tests with allergens known to elicit IgE-mediated reactions and the evaluation of eczematous skin lesions. APT can be performed on normal uninvolved skin without artificial manipulations such as tape stripping or use of irritants. APT has been standardized regarding the use of vehicle and dose response relationships. Positive APT reactions were significantly more frequent in pati-ents with a typical air-exposed eczematous distri-bution pattern. Using evaporimetry to study trans-epidermal water loss, allergeninduced disturbance of epidermal barrier functions was found to be significantly more pronounced on APT reactions compared to classical contact allergy patch test sites in the same individual. It has been shown that with APT eczematous skin lesions can be elicited by skin contact with aeroallergens, at least in a subgroup of patients with AE, and thereby, that IgE-mediated allergy does play a role in the etiopatho-physiology of this disease.
s20. S20-2
Geriatric dermatology Changes
in skin pigmentation
J.-P. Ortonne. U3M INSERM, I S19 4 Systemic children
protein
Kristiina Turjanmaa. Department University
Hospital,
Tampere,
contact
dermatitis
of Dermatology,
in Tampere
Finland
Patch testing with aeroallergens has been found to be a useful model to study the inflammatory reaction in atopic eczema (AE). Recently, protein patch tests (PPT) with cow milk (CM) powder have been used in children with AE and/or gastrointestinal (GI) symptoms and were found to be more often positive in children with delayed-type reactions to CM challenge, whereas skin prick test- or RAST-positive children more often react immediately to challenge. The elimination-challenge procedure is the only relevant diagnostic test for food allergy/intolerance. The problem at present is that most children show multiple food sensitization, and extensive elimination diets are needed to get the skin or the GI tract symptomless for the challenge tests. Skin tests can be used to plan these diets, but prick tests and RAST are known to have low sensitivity and specificity in children with AE. Therefore, PPT seems to bring more information. Majamaa, Holm and Turjanmaa (unpublished) analyzed PPTs in 69 milk challenge-positive infants: 30 were milk powder PPTpositive and 27130 showed negative skin prick test or RAST to CM. Although the sensitivity and specificity of PPTs have not been extensively studied, they seem to give additional information for use in planning elimination diets before challenge. Speculatively, PPT with foods could be regarded as a method for diagnosing systemic protein contact dermatitis where the contact takes place in the GI tract, and antigen-specific T cells then selectively migrate to the skin causing AB in genetically predisposed persons.
and
Germany
Dermatologie,
Hepita
in the elderly
Facult6 de Mdecine, de L’Archet, Nice, France
Service
de
Chronological aging, as well as photoaging modifies the melanocyte system of the skin. In the epidermis and the hair, melanin pigment are good indicators of aging. Uneven pigmentation is one of the major aging features in gross morphology of the skin and is more marked in exposed skin, indicating that W-irradiation plays a major role in the induction of these modifications. Thus dyspigmentation is one of the main clinical features distinguishing photodamaged skin from inhinsicalIy aged skin. Despite the decreased melanocyte density, photoaged skin has irregular pigmentation and, frequently there is hypetpigmentation. This may be due to greater melanogenic activity of some chronically irradiated melanocytes. The most common pigmented lesions in sun-exposed skin include ephelides, actinic lentigo, sunbeds lentigines, pigmented solar keratoses and seborrhoeic keratoses, pigmented epithehomas and lengigo maligna. Lesions of erythromelanosis interfolIicuhuis are very often heavily pigmented. Exposure to W-radiation also seems to play a role in the manifestation of acquired naevi. The white spots in aged skin are usually stellate pseudoscam or idiopathic guttate hypomelanosis. Medical treatment of dyspigmentation of photoaged skin includes topical tretinoin and depigmenting agents, and to a lesser extent alpha-hydroxy-acids. Surgical procedures such as liquid nitrogen cryotherapy. chemexfoliation with tichloroacetic acid, phenol or alpha-hydroxy-acids, dermabrasion and laser resurfacing and surgical ablation with the recently developed pigment-specific lasers are also widely used. Last but not least, prevention should begin in early childhood and extend throughout life (limitation of mid day sun-exposure, WA and WB sunscreens, photoprotective clothing...).