OBJECTIVE: We sought to understand the mechanisms of eczema in DOCK8 deficiency.
METHODS: Skin biopsy samples were characterized by histology, immunofluorescence microscopy, and gene expression. Skin barrier function was measured by transepidermal water loss. Allergic skin inflammation was elicited in mice by epicutaneous sensitization with ovalbumin (OVA) or cutaneous application of Staphylococcus aureus.
RESULTS: Skin lesions of DOCK8-deficient patients exhibited type 2 inflammation, and the patients' skin was colonized by Saureus, as in AD. Unlike in AD, DOCK8-deficient patients had a reduced FOXP3:CD4 ratio in their skin lesions, and their skin barrier function was intrinsically intact. Dock8-/- mice exhibited reduced numbers of cutaneous T regulatory (Treg) cells and a normal skin barrier. Dock8-/- and mice with an inducible Dock8 deletion in Treg cells exhibited increased allergic skin inflammation after epicutaneous sensitization with OVA. DOCK8 was shown to be important for Treg cell stability at sites of allergic inflammation and for the generation, survival, and suppressive activity of inducible Treg cells. Adoptive transfer of wild-type, but not DOCK8-deficient, OVA-specific, inducible Treg cells suppressed allergic inflammation in OVA-sensitized skin of Dock8-/- mice. These mice developed severe allergic skin inflammation and elevated serum IgE levels after topical exposure to Saureus. Both were attenuated after adoptive transfer of WT but not DOCK8-deficient Treg cells.
CONCLUSION: Treg cell dysfunction increases susceptibility to allergic skin inflammation in DOCK8 deficiency and synergizes with cutaneous exposure to Saureus to drive eczema in DOCK8 deficiency.
METHODS: This is a five-year retrospective review on contact sensitisation in adults patch-tested with the European Standard and extended series between 2011 and 2015 in the Department of Dermatology, Hospital Kuala Lumpur.
RESULTS: There were 689 adults (M:F= 1:2.04; mean age 40.5 years) who were patch-tested. The majority (175, 25.4%) were white collar workers and 118 (17.1%) were healthcare workers. The provisional diagnoses of patients included contact dermatitis (80.8%); endogenous eczema (7.9%); hand eczema (3.2%); hand and foot eczema (3.5%); foot eczema (1.4%) and photodermatitis (1.2%). The allergens selected for testing were based on past and present history of exposure. Almost all (688, 99.8%) were patch-tested with the European standard allergens and 466 (67.6%) were tested with the extended series. About three quarter (528, 76.6%) developed at least one positive reaction. The top five most frequent reactions were to nickel sulphate (35.3%); potassium dichromate (16.5%); methylchloroisothiazolinone (12.9%), fragrance mix I (12.6%), and cobalt chloride (10.2%). The commonest sensitisations identified in the extended series were palladium chloride (23/105, 21.9%), stannous chloride (18/85, 21.2%), miconazole (7/44, 15.9%), gold(I)sodium thiosulfate (16/105, 15.2%) and thimerosal (29/202, 14.4%).
CONCLUSION: Contact sensitisation was detected in 76.6% of adults patch-tested. Nickel sulphate was found to be the most frequently sensitising allergen. The rising prevalence of methylchloroisothiazolinone/methylisothiazolinone sensitization poses significant concern.
OBJECTIVES: We aim to determine relevant seafood sensitization among adults with AD and investigate cross-sensitization to aeroallergens.
METHODS: One hundred thirty-two adults with AD who were subjected to skin prick test (SPT) with 7 common local seafood allergens (anchovy, tuna, mackerel, squid, giant freshwater prawn, shrimp, and crab), house dust mites (HDMs), and cockroach were analyzed retrospectively.
RESULTS: The median age of the study subjects was 32 years (range 17-77 years) with a male to female ratio of 1:3. The mean duration of AD was 16 years. Eighty-two patients (62.2%) had other atopic conditions. Using SCORAD, 44.7% had mild, 42.4% moderate, and 12.9% severe disease. Eighty-six patients (65.2%) self-reported to have seafood allergy, with the main symptoms of transient pruritus and erythema within 2 h of ingestion. SPT revealed 51.5% of the patients were sensitized to at least 1 of the 7 seafood allergens. The relevant sensitization rate was 45.1%. Interestingly, 46% of those without a history of seafood allergy developed at least 1 positive reaction in the SPT. Prawn, shrimp, and crab were the 3 most frequently sensitized allergens. Nearly all patients (98.3%) who were sensitized to crustaceans were also sensitized to HDMs and/or cockroach. There was no significant correlation between a positive SPT to seafood with age, age of onset of AD, duration, and severity of AD, and the presence of other atopic diatheses.
CONCLUSION: The relevant sensitization rate of local seafood among adults with AD was 45.1%.