Urticaria

Quality of life may be serve and in most pts the average disease for lasts how long?

2-5 yrs. Rate of spontaneous remission at one year is about 30-50 percent.

What are some examples of 2nd generation antihistamines

Cetririzine Loratagine Fexofenadine

What is the best tx for urticaria?

Daily oral 2nd generation H1 antihistamines (Loratadine). Better tolerated with few sedative effects. Kiddos and elderly, renal pts will require dosage adjustments.

Angioedema common affects where?

Face or part of extremity. Angioedema can be caused by the same pathogenic mechanisms as urticaria, but the pathology is in the deep dermis and subcutaneous tissue and swelling is the major manifestation Involvement of the lips, cheeks, and periorbital areas is common, but angioedema also may affect the tongue, pharynx, larynx and bowels May be painful or burning, but not pruritic May last several days

What is the treatment for anaphylaxis

First Line-epiephrine, IV fluids, and O2 AIRWAY!

Causes of Acute Urticaria

Idiopathic Infection Upper respiratory, streptococcal infections, helminthes Food reactions Shellfish, nuts, fruit, etc. Drug reactions IV administration Blood products, contrast agents

Causes of Chronic Urticaia

Idiopathic: over 50% of chronic urticaria Physical urticarias: many patients with chronic urticaria have physical factors that contribute to their urticaria These factors include pressure, cold, heat, water (aquagenic), sunlight (solar), vibration, and exercise Cholinergic urticaria is triggered by heat and emotion The diagnosis of pure physical urticaria is made when the sole cause of a patient's urticaria is a physical factor Chronic autoimmune: possibly a third or more of patients with chronic urticaria Other: infections, ingestions, medications

Clinical Findings for Urticaria

Lesions typically appear over the course of minutes, enlarge, and then disappear within hours Individual wheals rarely last >12hrs Surrounding erythema will blanch with pressure Urticaria may be acute or chronic Acute = new onset urticaria < 6 weeks Chronic = recurrent urticaria (most days) > 6 weeks Most urticaria is acute and resolves

What is the major effector cell in urticaria

Mast cell. Immunologic Urticaria: antigen binds to IgE on the mast cell surface causing degranulation, and releases histamine.

Dermatographism

Most common form of physical urticaria Sharply localized edema or wheal within seconds to minutes after the skin has been rubbed Affects 2-5% of the population

Is allergy testing performed in pts with chronic urticaria?

No. Skin prick may reveal sensitivities to allergens that may not be related to pts urticaria. Lab test may id the 1/3 of pts with chronic urticaria with autoimmune path. This adds cost.

Medication induced Urticaria is common in urticaria and angioedema. What are the main meds?

PCN and related antibiotics via IgE mediated. Aspirin-nonIgE mediated Detergent use is an irritant or allergic contact term, not urticaria

What is an essential part of the exam with skin lesions/hives?

Respiratory. Ask about sum of anaphylaxis. Chest tightness, hoarse voice, abdominal pain, lightheadedness. Vitals. For acute urticaria, not lab testing required

Urticaria

Urticaria (hives) is a vascular reaction of the skin characterized by wheals surrounded by a red halo or flare (area of erythema) Cardinal symptom is PRURITUS (itch) Urticaria is caused by swelling of the upper dermis

When do you refer to derm and what should you do?

When you have no idea what the hell you are looking at. Biopsy that bitch. Lesions persist beyond 48hrs, and painful Systemic symptoms Lack of response to antihistamines Lesions that leave pigmentation changes upon resolution

What is anaphylaxis

serious allergic reaction that is rapid in onset and may cause death. No lesions may be present. ABC!!!