I The vascular responses of human skin to two synthetic analogues of histamine, 2-methyl histamine (an HI-receptor agonist) and 4-methyl histamine (an H2-receptor agonist) have been studied in vivo.2 Both compounds evoked dose-related erythema, 2-methyl histamine but not 4-methyl histamine causing erythema mediated by an axon reflex, thus suggesting that the axon reflex and direct vasodilator action of histamine are due to HI and H2 actions respectively. 3 The H,-receptor antagonist chlorpheniramine inhibited erythema due to 2-methyl histamine.Cimetidine, an H2-receptor antagonist, had no effect on the reaction to 2-methyl histamine. In contrast, the erythema reaction to 4-methyl histamine was suppressed by both cimetidine and chlorpheniramine. 4 Although both histamine analogues caused wealing, this was not dose-related within the dose range used, and neither chlorpheniramine nor cimetidine caused detectable suppression ofwealing responses to either histamine analogue.S These results lend further support to the view that human skin blood vessels possess H2 as well as H, receptors.
Mango Dermatitis' is the common term given to allergic contact dermatitis to the sap or skin of the fruit of Mangifera indica. Four patients presented with urticaria and eczematous rash following exposure to mangoes or the trees. Patch testing with diluted sap, crushed leaf, crushed stem and fruit skin was strongly positive.
Graft-versus-host disease (GVHD) occurs in a number of clinical settings. It is well recognized after bone marrow transplantation, an increasingly used therapeutic option for haematological disorders. Chronic GVHD, occurring at an interval greater than 100 days post-transplant, has many systemic manifestations, but it is the cutaneous manifestations which are most frequent and often most troubling to the patients. In this review article, the wide spectrum of cutaneous chronic GVHD (including involvement of hair, nails and mucosae), and its complications and associations are discussed. The clinical and histological features and management guidelines are presented to assist the dermatologist with diagnosis and treatment of this condition.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.