Michael D. Howell

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BACKGROUND Atopic dermatitis (AD) is a chronic inflammatory skin disease that is characterized by a defective skin barrier function. Recent studies have reported mutations of the skin barrier gene encoding filaggrin in a subset of patients with AD. OBJECTIVE We investigated whether reduced filaggrin expression was found in patients with AD who were not(More)
Atopic dermatitis is a chronic inflammatory skin disease associated with cutaneous hyperreactivity to environmental triggers and is often the first step in the atopic march that results in asthma and allergic rhinitis. The clinical phenotype that characterizes atopic dermatitis is the product of interactions between susceptibility genes, the environment,(More)
Atopic dermatitis (AD) and psoriasis are the two most common chronic skin diseases. However patients with AD, but not psoriasis, suffer from frequent skin infections. To understand the molecular basis for this phenomenon, skin biopsies from AD and psoriasis patients were analyzed using GeneChip microarrays. The expression of innate immune response genes,(More)
BACKGROUND The cathelicidin family of antimicrobial peptides is an integral component of the innate immune response that exhibits activity against bacterial, fungal, and viral pathogens. Eczema herpeticum (ADEH) develops in a subset of patients with atopic dermatitis (AD) because of disseminated infection with herpes simplex virus (HSV). OBJECTIVE This(More)
Possible bioterrorism with smallpox has led to the resumption of smallpox (vaccinia virus) immunization. One complication, eczema vaccinatum, occurs primarily in patients with atopic dermatitis (AD). Skin lesions of patients with AD, but not psoriasis, is deficient in the cathelicidin antimicrobial peptide (LL-37) and human beta-defensin-2 (HBD-2). We(More)
BACKGROUND IL-31 is a newly discovered T-cell cytokine that, when overexpressed in mice, results in pruritus and skin dermatitis resembling human atopic dermatitis (AD). OBJECTIVE We sought to investigate the expression of IL-31 and IL-31 receptor A (IL-31RA) in skin biopsy specimens and peripheral blood cells from patients with AD and healthy(More)
Atopic dermatitis (AD) is characterized by a defective skin barrier which allows increased allergen and pathogen penetration. Loricrin (LOR) and involucrin (IVL) are proteins important for skin barrier formation and integrity. In this study, we demonstrate that the gene and protein expression of LOR and IVL is significantly decreased in involved (LOR:(More)
Cathelicidins and other antimicrobial peptides are deployed at epithelial surfaces to defend against infection. These molecules have broad-spectrum killing activity against microbes and can have effects on specific mammalian cell types, potentially stimulating additional immune defense through direct chemotactic activity or induction of cytokine release. In(More)
IL-4 promotes the development of Th2 cells and allergic inflammation. In atopic dermatitis lesions, IL-4 decreases the expression of multiple genes associated with innate defense, including genes in the epidermal differentiation complex (EDC) that regulate epidermal barrier function. However, it is not clear whether IL-4 also contributes to homeostatic(More)
Atopic dermatitis (AD) is associated with eczema vaccinatum (EV), a disseminated viral skin infection that follows inoculation with vaccinia virus (VV). This study examined whether AD skin can control VV replication, and the role of IL-4 and IL-13 in modulating the human cathelicidin LL-37, an antimicrobial peptide that kills VV. AD skin exhibited increased(More)