URTICARIA (HIVES) Prof.Dr.Reha Cengizlier

Definition Acute or chronic, itchy, red colored, different shaped skin reactions Affect superficial skin (epidermis) If dermis being affected; edema occurs and named as “angioedema” Sometimes together, sometimes separated

Acute-Chronic Skin lesions that last less than 6 wk duration are considered acute, and episodes that persist for more than 6 wk are designated chronic

Etiology-1 Food and drug reactions Inhalant allergens Infections Collagen vascular diseases and cutaneous vasculitis Malignancy with angioedema Cold urticaria Solar urticaria

Etiology-2 Dermatographism Pressure urticaria Vibratory angioedema Aquagenic urticaria Hereditary angioedema Familial cold urticaria C3b inactivator deficiency Chronic idiopathic urticaria

Acute urticarial lesions last in 1–2 hr There is prompt mast cell degranulation, and biopsy of such lesions reveals little or no cellular infiltrate

Chronic urticaria has a prominent cellular infiltrate, and individual lesions can last as long as 36 hr This can be found with food or drug reactions, delayed pressure urticaria, and chronic urticaria, serum sickness reaction, SLE and other vasculitis syndromes

Urticaria or angioedema may be the manifestation of a more systemic disease process Lesions that do not blanch or are associated with bleeding into the skin (i.e., purpura) suggest urticarial vasculitis

Diagnosis Drugs and foods are the most common causes of acute urticaria (URI for children) The diagnosis is clinical and requires that the physician be aware of the various forms of urticaria

The differential diagnosis of chronic urticaria Cutaneous or systemic mastocytosis, Complement-mediated disorders, Malignancies, Mixed connective tissue diseases, Cutaneous blistering disorders (e.g., bullous pemphigoid)

The differential diagnosis of chronic urticaria Skin biopsy for diagnosis of possible urticarial vasculitis is recommended for urticarial lesions that persist at the same location for more than 24 hr or those with pigmented or purpuric components

Urticaria pigmentosa The most common skin manifestation of mastocytosis and may occur as an isolated skin finding It appears as small, yellow to reddish- brown macules or raised papules that urticate on scratching (Darier sign) The diagnosis is confirmed by a skin biopsy that shows increased numbers of dermal mast cells

Treatment Acute urticaria is a self-limited illness requiring little treatment other than antihistamines Sedating (children) non-sedating (adult) antihistamines commonly used for treatment of urticaria Epinephrine 1:1,000, 0.01 mL/kg, maximum of 0.3 mL, usually provides rapid relief of acute, severe urticaria/angioedema A short burst of corticosteroids should be given only for very severe episodes of urticaria and angioedema

ATOPIC DERMATITIS Atopic Dermatitis (AD) is a highly pruritic skin disease that affects more than 10% of children It is frequently associated with elevated serum IgE levels, and nearly 80% of patients with AD develop allergic rhinitis and/or asthma

Pathogenesis Complex interactions between genetic, environmental, and immunologic factors contribute to the pathogenesis of AD Current therapies in AD have evolved from an understanding of the pathobiology of this disease

Tutulmamış AkutKronik Allerjenler Kaşınma Mikrobial toksinler Sitokin ve kemokinler CLA + Th2 hücreler Eozinofiller Dolaşım Leung DY, Boguniewicz M, et al. J Clin Invest 2004 TSLP: Thymic Stromal Lymphopoietin CLA: Cutaneous Lymphocyte-associated Antigen IDEC:Inflammatory Dendritic Epidermal Cell LC: Langerhans Cell MC: Mast Cell

GENETICS AD is familially transmitted with a strong maternal influence

Clinical Manifestations AD typically begins during infancy Approximately 50% of patients develop this illness by the first year of life, and an additional 30% are diagnosed between 1–5 yr of age Intense pruritus and cutaneous reactivity are cardinal features of AD Pruritus is usually worse at night Its consequences are scratching that contributes to the induction of eczematous skin lesions Foods, inhalant allergens, bacterial infection, reduced humidity, excessive sweating, and irritants (e.g., wool, acrylic, soaps, and detergents) can exacerbate pruritus and scratching

Diagnosis Pruritus and chronic remitting eczematous dermatitis with typical morphology and distribution are essential for the diagnosis of AD Other associated features, including a family history of asthma, hay fever, elevated IgE, and immediate skin test reactivity, are variable

Differential diagnosis Inflammatory skin diseases Immunodeficiencies Skin malignancies Genetic disorders Infectious diseases Infestations

Differential diagnosis-2 Histiocytosis X should be ruled out in any infant with AD and failure to thrive Wiskott-Aldrich syndrome is an X-linked recessive disorder, associated with thrombocytopenia, immune defects, and recurrent severe bacterial infections, characterized by a rash almost indistinguishable from AD The hyper-IgE syndrome is characterized by markedly elevated serum IgE levels, recurrent deep-seated bacterial infections, chronic dermatitis, and recalcitrant dermatophytosis

Treatment The treatment of AD requires a systematic, multifaceted approach that incorporates skin hydration, topical therapy, identification and elimination of flare factors, and, if necessary, systemic therapy

Systemic therapy Antihistamines Systemic Glucocorticoids Cyclosporine Interferons

Prognosis AD generally tends to be more severe and persistent in young children Periods of remission appear more frequently as the patient grows older Spontaneous resolution of AD has been reported to occur after age 5 yr in 40– 60% of patients affected during infancy, particularly if their disease is mild

Prevention Identification and elimination of triggering factors as part of treatment of AD is also the mainstay of prevention of recurrences