urticaria (cqc)

18
CQC MAY 26, 2009 KEVIN POLSLEY, MD MEDICINE PEDIATRICS PGY2 It Itches!

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Page 1: Urticaria (CQC)

CQCMAY 26, 2009

KEVIN POLSLEY, MDMEDICINE PEDIATRICS PGY2

It Itches!

Page 2: Urticaria (CQC)

Clinic Visit

CJ is a 17 year old maleClinic visit for school physicalPreviously healthy with no significant PMHComplains of itchy red rashRash has been present for the past six weeksHe has noticed several exacerbating factors:

Tight clothing Cold weather Exercise

The rash comes and goes quickly

Page 3: Urticaria (CQC)

Clinic Visit Continued

ROS, PMH, FHx, SHx all negativeExam:

Vitals normal Lungs CTA Heart RRR, no murmur Abdomen soft, ND/NT, no organomegaly Skin: normal, then…

Page 4: Urticaria (CQC)

Clinical Question:

What is the significance of urticaria that has been present

for 6 weeks?

Page 5: Urticaria (CQC)

Urticaria

Recurrent, generalized, erythematous, pruriticCircumscribed borders, blanch with pressureIncidence: 15% to 25%Wheal (edema) and flare (erythema)Acute: less than 6 weeks durationMorbidity:

swelling, itching, and pain impact on mobility, self-image, and social interactions

Strongly associated with angioedema (40%)

Page 6: Urticaria (CQC)

Differential Diagnosis

Viral exanthemsAtopic dermatitisContact dermatitisErythema multiformePityriasis roseaMastocytosis/MastocytomaUrticaria pigmentosa

Page 7: Urticaria (CQC)

Mechanisms

Immune mediated (IgE hypersensitivity)Complement mediatedNon-immune mediated (degranulation of mast

cells by something other than IgE)Autoimmune mediatedUnkown

Idiopathic Infection Medications Systemic illnesses (some)

Page 8: Urticaria (CQC)

Acute Urticaria

More common in young childrenSpecific cause is more likely to be identifiedFrequently attributed to viral infections,

medications, or foods Younger children: egg, milk, soy, peanut, and wheat Older children: fish, seafood, nuts, and peanuts Food-induced contact urticaria with atopic dermatitis

Transient natureExtensive assessment usually unnecessary

Page 9: Urticaria (CQC)

Chronic Urticaria

More common in adultsCause is determined in less than 20% of

casesCauses include:

Physical urticaria Autoimmune urticaria Medications

May be sign of systemic illness: Thyroid dysfunction Vasculitis Connective tissue disease Lymphoproliferative disorders

Page 10: Urticaria (CQC)

Chronic Urticaria: Physical

Dermographism: 2-5% of general population IgE mediated? No allergen identified No systemic symptoms

Cholinergic Precipitated by heat, exertion, and emotional factors May have systemic symptoms (wheezing, angioedema) Mast cell activation

ColdDelayed PressureSolar (less common)Aquagenic (uncommon)

Page 11: Urticaria (CQC)

Dermographism on Flickr

Page 12: Urticaria (CQC)

Chronic Urticaria: Systemic Illness

Autoimmune thyroid disease Hashimotos > Graves Mechanism unknown 19% have abnormal TFTs; unclear significance

Vasculitis SLE

Malignancy Lymphoproliferative disorders Sweet's syndrome (acute febrile neutrophilic

dermatosis) Cryoglobulinemia

Buttocks and LEs; HCV infectionH pylori gastritis

Page 13: Urticaria (CQC)

Evaluation: History

Viral infectionRecent insect bites or stingsBlood transfusionSuspected foodsSkin contact to foreign material, heat, cold,

waterHyper/Hypothyroid symptomsMedications (Alcohol, NSAIDs, opiates, ACEs)Other symptoms such as lip swelling

(angioedema)

Page 14: Urticaria (CQC)

Evaluation: Exam

Dermographism: linear whealsCholinergic: small wheals surrounded by

erythemaSolar or cold: limited to exposed areasPressure or urticarial vasculitis: wheals on

LEsCold provocation test:

Placing an ice cube to the forearm for 4 minutes Development of urticaria during rewarming

Warm arm bath

Page 15: Urticaria (CQC)

Evaluation: Labs

Acute: allergen testing as directed by history

Chronic: directed by findings ANA TFTs and anti-thyroid antibodies CBC with differential ESR Meta-analysis: no correlation between number of

tests performed and number of diagnoses identified

Page 16: Urticaria (CQC)

Treatment

Avoidance of triggersFirst line therapy are anti-histaminesH1 blockers: 85% of cutaneous receptors

1st gen: diphenhydramine, hydroxyzine, chlorpheniramine 2nd gen: Loratadine, cetirizine, desloratatine,

fexofenadineH2 blockers: 15% of cutaneous receptors

Ranitidine or cimetidine Mizolastine (Europe)

Combination of above medications if necessary 2nd generation in the morning, 1st generation at night

Page 17: Urticaria (CQC)

Alternative Treatments

Leukotriene receptor antagonists: Improve hives and swelling compared with placebo RCT: desloratadine vs. montelukast vs. both showed

no benefit with combo therapy vs. desloratadine monotherapy

Corticosteroids (lowest effective dose) Urticarial vasculitis Delayed pressure urticaria Alternate day dosing

Cyclosporine Low dose (2.5 – 3 mg/kg/day)

Ketotifen (mast cell stabilizer)

Page 18: Urticaria (CQC)

References

Grattan, Clive. “Autoimmune Urticaria.” Immunol Allergy Clin North Am., 2004 May;24(2):163-81.

Kaplan, Allen. “Clinical practice. Chronic urticaria and angioedema.” N Engl J Med., 2002 Jan 17;346(3):175-9.

Rumbryt, Jeffrey. “Chronic Urticaria and Thyroid Disease.” Immunol Allergy Clin North Am., 2004 May;24(2):215-223.

Dice, John. “Physical Urticaria.” Immunol Allergy Clin North Am., 2004 May;24(2):225-246.

Zuberbier, T. “Urticaria.” Allergy. 2003 Dec;58(12):1224-34. Muller, BA. “Urticaria and angioedema: a practical approach.” Am

Fam Physician. 2004 Mar 1;69(5):1123-8. Baxi, Sachin. “Urticaria and Angioedema.” Immunol Allergy Clin

North Am., 2004 May;24(2):353-367.