Chronic Idiopathic Urticaria

Author: V. Dimov, M.D., Allergist/Immunologist and Assistant Professor at University of Chicago
Reviewer: S. Randhawa, M.D., Allergist/Immunologist and Assistant Professor at LSU (Shreveport) Department of Allergy and Immunology

A 27-year-old year CM is referred to the allergy clinic for symptoms of hives for 2 months. Hives are described as a raised and itchy skin rash that occurs on the entire body with each individual hive lasting less than 24 hours. The lesions are pruritic and not painful. They heal without residual bruising or hyperpigmentation. Possible triggers have not been identified.

The patient has tried prescription antihistamines but they did not offer adequate control of symptoms. He has had several episodes of lip swelling but no throat or laryngeal involvement. The patient has required ER evaluation and treatment for these symptoms. A skin biopsy has not been performed.

Past Medical History (PMH)



No known medication allergy.


Hydroxyzine (Vistaril, Atarax) 25 mg po tid prn itching.

Family Medical History (FMH)

Hay fever - mother.

Physical examination

HEENT: External ears normal. Canals clear. TM's normal. Nasal mucosa normal. No drainage or sinus tenderness. Lips, tongue normal. Oropharynx clear.
Neck: supple, no adenopathy.
CVS: RRR, normal S1/S2, no m/r/g.
Chest: CTA (B).
Extremities: no c/c/e.
Skin: Hives on both arms.

Figure 1. Urticaria appearing on right arm. Image source: Wikipedia, public domain.

What is the most likely diagnosis?

Chronic urticaria.

What would you do?

Screening lab work.
H1- and H2-blockers.

What happened?

The patient declined further lab work. He was prescribed Allegra 180mg BID and Pepcid 20 mg po BID. He was advised that he could use OTC Claritine (loratadine) instead of Allegra. He was asked to avoid Atarax if going to work or driving.

The patient was instructed to call the office if there is no improvement in his symptoms and a follow-up in 2 months was arranged.

Final diagnosis

Chronic Idiopathic Urticaria.


Mind map diagram of chronic urticaria.

Diagnosis of Chronic Urticaria (click to enlarge the image).

Anti-FceR1 autoantibodies in chronic autoimmune urticaria: IgG against FceRI (receptor for IgE) (click to enlarge the image).

Chronic spontaneous urticaria (CSU) is defined as the presence of urticaria with daily or almost daily symptoms for 6 weeks or more. CSU affects 0.1%-0.8% of the population.

Therapy for chronic spontaneous urticaria


1 Nonsedating, second- or third-generation antihistamines taken 4 times a day. Decrease the dose as tolerated once control of symptoms is attained. Dose of cetirizine, loratadine, desloratadine, or levocetirizine corresponding to hydroxyzine or diphenhydramine at 50 mg 4 times daily is 6 tablets per day. If response inadequate, proceed to step 2.

2 Omalizumab, 300 mg monthly. If no response after 2 injections, proceed to step 3.

3 Cyclosporine, 200-300 mg/d

4 Options to consider if steps 1-3 fail: dapsone, methotrexate, sulfasalazine, hydroxychloroquine, intravenous γ-globulin, and plasmapheresis.

Expected response rate based on the literature. Patient response to step 1 was 45%. Patient response to step 2 was 65% of the remainder. Calculated response rate of steps 1 plus 2 was 81%. Patient response to step 3 was 65% of the remainder. Calculated total response rate for steps 1, 2, and 3 was 92%. Source: Therapy of chronic urticaria: a simple, modern approach. Allen P. Kaplan, Annals of Allergy, Asthma & Immunology, Volume 112, Issue 5, Pages 419–425, May 2014,


Urticaria: A Short Review. V. Dimov. Clinical Notes in Allergy and Immunology.
Anti-FceR1 Autoantibodies in Chronic Urticaria
Chronic Idiopathic Urticaria. Current Opinion in Allergy and Clinical Immunology, Medscape, 2003.
Acute and chronic urticaria. Krishnaswamy G, Youngberg G. Postgrad Med 2001;109(2):107-23.
Urticaria. eMedicine, 2004.
Allergy and the skin. Urticaria. ABC of allergies. BMJ 1998;316:1147.
Urticaria. Merck Manual.
Image source: Uricaria appearing on right arm, Wikipedia, public domain.

Published: 09/14/2007
Updated: 11/19/2011


Anonymous said...

Hi I have been suffering from CIU for the last 2 months, I have been tested for auto immune disease (ANA), kidney function, skin allergy test and chemical patch test, but all the tests came out negative, except for minor cockroach allergy positive. I had a similar episode 2 years back, which lasted for nearly 6 months. Right now im on Clarinex 10 mg and Xyzal 10 mg. Have been on courses of Prednisone, and medrol for 8 days. Despite all these Hives keep comming back. Would really appreciate if you could suggest any further tests to figure out the cause for CIU.

Anonymous said...

Try a breath test for H Pylori?

Anonymous said...

Sure. You can do a whole set of tests. Please see the mind map diagram above.

Anonymous said...

This is very frustrating to me. My 8 year old son has had constant hives now for nearly two years, the frequency and duration of the hives changes but they always come back! Sometimes the hives are localized, other times they cover him from head to toe. My wife and I had some blood work done on him via a naturalpath and the tests results indicated an allergic reaction to wheat, gluten, dairy, garlic, citrus and eggs. We restricted his diet from these foods and did see an improvement in his symptoms and how long they would last. However, a recent skin test at the allergist says he is not allergic to these foods. The allergist is guessing he has Chronic Idiopthic Urticaria. Are there other ways to diagnosis this specifically as I feel so badly for him and am just looking for answers! Thanks

Anonymous said...

The best approach is to ask your allergist about chronic idiopathic urticaria (CIU).

The positive and negative predictive values of the autologous serum skin test (ASST) in CIU patients are 53 and 70%, respectively.

27-50% of patients with CIU have autoantibodies against the α-chain of the high-affinity IgE receptor (FceRI) or less commonly against IgG.

Those are 2 starting points. Xolair is a new therapetic option.

Anonymous said...

Look into salicylate reaction. I have had CIU for the past 5 years consistently. Only recently did I learn that it is the result of low salicylate level sensitivity. I had been taking naproxen for a long time. But salicylates are in everything shampoo, food, aspirin, Motrin, food dyes, sun screen. It wasn't until I put on sunscreen that had this as the main ingredient, my throat started closing within 10 mins of putting on the sunscreen. Best of luck to you in finding your source.

Anonymous said...

I 2nd the opinion on looking into salicylate reactions. The hives & the salicylate sensitivity go hand and hand in my family too. It really is not easy because salicylates are in most every thing that is deemed good for you, as well as many skin care products. If taking asprin, which is salicylic asprin has adverse effects, then you may be salicylate intolerant.