URTICARIA(HIVES)

Prof.Dr.Reha Cengizlier7.11.2014

Definition

Acute or chronic, itchy, red colored, different shaped skin reactionsAffect 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-1Food and drug reactionsInhalant allergensInfectionsCollagen vascular diseases and cutaneous vasculitisMalignancy with angioedemaCold urticariaSolar urticaria

Etiology-2DermatographismPressure urticariaVibratory angioedemaAquagenic urticariaHereditary angioedemaFamilial cold urticariaC3b inactivator deficiencyChronic idiopathic urticaria

Acute urticarial lesions last in 1–2 hrThere 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 hrThis 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 processLesions 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

TreatmentAcute urticaria is a self-limited illness requiring little treatment other than antihistaminesSedating (children) non-sedating (adult) antihistamines commonly used for treatment of urticariaEpinephrine 1:1,000, 0.01 mL/kg, maximum of 0.3 mL, usually provides rapid relief of acute, severe urticaria/angioedemaA 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 childrenIt 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 ADCurrent therapies in AD have evolved from an understanding of the pathobiology of this disease

Tutulmamış Akut Kronik

AllerjenlerKaşınma

Mikrobial toksinler

Sitokin ve kemokinler

CLA+Th2 hücreler Eozinofiller

Dolaşım

Leung DY, Boguniewicz M, et al. J Clin Invest 2004TSLP: Thymic Stromal LymphopoietinCLA: Cutaneous Lymphocyte-associated AntigenIDEC:Inflammatory Dendritic Epidermal CellLC: Langerhans Cell MC: Mast Cell

GENETICS

AD is familially transmitted with a strong maternal influence

Clinical ManifestationsAD typically begins during infancyApproximately 50% of patients develop this illness by the first year of life, and an additional 30% are diagnosed between 1–5 yr of ageIntense pruritus and cutaneous reactivity are cardinal features of ADPruritus is usually worse at nightIts consequences are scratching that contributes to the induction of eczematous skin lesionsFoods, 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 ADOther associated features, including a family history of asthma, hay fever, elevated IgE, and immediate skin test reactivity, are variable

Differential diagnosis

Inflammatory skin diseasesImmunodeficiencies Skin malignancies Genetic disorders Infectious diseases Infestations

Differential diagnosis-2Histiocytosis X should be ruled out in any infant with AD and failure to thriveWiskott-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 ADThe 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

AntihistaminesSystemic GlucocorticoidsCyclosporineInterferons

Prognosis AD generally tends to be more severe and persistent in young childrenPeriods of remission appear more frequently as the patient grows olderSpontaneous 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