Why Won’t My Hives Go Away?

Hives, or urticaria, are raised, often itchy welts or bumps. They appear when a trigger in the body (sometimes known and other times unknown) causes mast cells in the skin to release high levels of histamine, serotonin, or some other chemicals.

When hives are present for more than six weeks without a known cause, the condition is called chronic idiopathic urticaria (CIU). This article will discuss chronic idiopathic urticaria, including its causes, diagnosis, treatment, and when to see a healthcare provider.

What Is Chronic Idiopathic Urticaria?

Chronic idiopathic urticaria is characterized by the appearance of hives—skin-colored welts or raised patches (angioedema)—that last for six or more weeks for no known reason. This condition is also called chronic spontaneous urticaria.

What Causes CIU?

The exact cause of chronic idiopathic urticaria is unknown, which can make getting a diagnosis frustrating and difficult.

Some research points to an altered gut microbiome (the balance of bacteria in your intestines) as a possible cause. This theory is based on the gut microbiome's important role in the function and regulation of the immune system. But more research needs to be done to determine the causal relationship between the two.

Known causes of urticaria, like systemic conditions (diabetes, hyperthyroidism, cancer), viral infection (hepatitis and herpes zoster infection), and bacterial infection (Helicobacter pylori), among others, must be ruled out in order before a diagnosis of CIU can be made.

CIU Diagnosis

CIU is a diagnosis of exclusion, meaning other causes must be ruled out before making this diagnosis. Therefore, the diagnosis of CIU may involve an extensive workup in looking for the underlying conditions that serve as a potential trigger of the disease.

Chronic idiopathic urticaria is a clinical diagnosis based on your symptoms using the following five criteria:

• Symptoms: These include the presence of intensely itchy hives, with well-circumscribed, raised weals. Associated symptoms such as pain and burning may also be present.  
• Medical history: A medical history specifically focuses on your allergies, contact with foreign substances and occupational hazards, past medical conditions, and the medications you are taking.
• Physical examination
• Duration: Symptoms have been experienced for six or more weeks.
• No specific or identifiable cause

No particular labs or tests need to be performed unless your medical history or physical examination detect specific underlying conditions as the cause of your symptoms. The healthcare providers most commonly making this diagnosis are primary care physicians or dermatologists (specialists in diseases of the skin, hair, and nails).

Treatment

Chronic urticaria is usually benign and, in some cases, may resolve on its own without the need for treatment. If there are triggers that you and your healthcare provider identify as potential causes, such as contact with a foreign substance or occupational exposure, these should be avoided.

Symptom management with medication is the mainstay of treatment. Chronic hives can cause significant discomfort, greatly affecting your quality of life. Medication may be considered to lessen the severity and duration of symptoms.

Histamine receptor blockers, namely second-generation H1 antihistamines such as Zyrtec (cetirizine), Xyzal (levocetirizine), and Claritin (loratadine) are first-line drugs for the condition.

You can purchase these over-the-counter (OTC) at your local pharmacy, although your healthcare provider often prescribes these medications with specific instructions on how to take them. They are also usually covered by your insurance.

Generally, your healthcare provider will prescribe the lowest, most effective dose possible. Over time, higher doses of the same or new medications may be prescribed if your symptoms have not improved.

If second-generation H1 antihistamines are not effective, one or more drugs from the following drug classes may be prescribed instead:

• First-generation H1 antihistamines such as Benadryl (diphenhydramine)
• H2 blockers such as Pepcid (famotidine) and Tagamet (cimetidine)
• Leukotriene receptor antagonists like Accolate (zafirlukast) and Singulair (montelukast)
• Xolair (omalizumab) or cyclosporine (may be used in cases that don't respond to antihistamines)
  

When to See a Healthcare Provider

If your itching is accompanied by any of the following symptoms, you should seek immediate medical attention. These may be signs of early anaphylactic shock (a life-threatening allergic reaction) or the presence of an underlying medical condition:

• Fever
• Chills
• Shortness of breath
• Swelling of the tongue, mouth, lips, or throat 
• Generalized pain or body aches
• Gastrointestinal symptoms such as nausea, vomiting, stomach cramps, or diarrhea

Summary 

Chronic idiopathic urticaria is the appearance of persistent hives that lasts for six or more weeks for no known reason. CIU is a diagnosis of exclusion, which means other causes must be ruled out before this diagnosis is made. Therefore, the diagnosis of CIU may involve an extensive workup looking for potential triggers of the disease.

A Word From Verywell

Hives usually go away on their own. When they last for six or more weeks, however, they may indicate an underlying medical condition requiring further medical evaluation.

If your symptoms do not change with conventional first-line treatments over the course of two weeks, follow up with your healthcare provider. They can evaluate you and direct you to the proper subspecialist who can look for the potential causes behind your hives.