Chronic hives vs allergies: When that persistent itch signals a bigger problem

A sudden, intense itching that came out of nowhere, accompanied by angry red hives and a burning sensation on her arms and legs.

This was how a female patient’s struggle with chronic spontaneous urticaria, also known as CSU or chronic hives, began in November 2020. The condition is not contagious.

The 35-year-old, referred to in this article as Patient R, is one of the 1 per cent globally affected by CSU. It can affect adults of all ages, but is more commonly seen in young to middle-aged adults, and tends to affect twice as many women than men, says Dr Lynn Chiam, consultant dermatologist, Mount Elizabeth Novena Hospital’s Children & Adult Skin Hair Laser Clinic. 

She shares: “CSU is a long-term skin condition where hives, or deep skin swelling (angioedema), or both, keep coming back over more than six weeks without a clear trigger. It is not just a simple allergy or heat rash, even though it may look similar at first.

“It usually appears as raised, itchy hives that can be red or skin-coloured. Some people also experience swelling of the lips, eyelids, hands or feet. The itching can be intense, sometimes described as burning or painful, and can disrupt sleep.”

The long road to a CSU diagnosis

Patient R initially tried to manage the condition on her own, enduring the itch and applying moisturising cream. However, the symptoms continued to reappear for more than six weeks, often without a clear trigger.

Explains Dr Chiam: “Unlike typical allergies, CSU is linked to inappropriate activation of the immune system, which causes repeated flare-ups even when no external trigger is found. Symptoms often come and go. 

“This on-and-off pattern makes many people think it is temporary. But when it keeps recurring for weeks or months, it is a chronic condition that deserves proper medical attention. In affected individuals, CSU can last for many months to a few years.”

These persistent recurrences prompted Patient R to visit a general practitioner (GP) for help.

Her condition was diagnosed by the GP as hives, and she was sent home with moisturising cream and steroid cream.

However, her condition did not appear to improve, so she sought treatment from two other GPs.

Both were similar in their approach. Patient R felt frustrated as her condition continued to affect her life, including her sleep, work productivity, travel and social activities.

Her confidence also took a hit, as she turned to wearing long-sleeved clothes to cover up, even in Singapore’s humidity, and even had to turn down important work assignments due to the incessant itch.

Notes Dr Chiam: “In Singapore, we see CSU regularly in clinical practice, although many cases are likely under recognised or mislabelled as simple hives. That is because CSU looks very similar to common conditions such as insect bites, heat rash, eczema or allergies; and because symptoms are temporary and the rash may even disappear after a few hours, the skin may look normal when a patient sees the doctor.”

Finally, in October 2021, the third GP that Patient R visited diagnosed her condition as CSU. She was given antihistamines, with the treatment gradually adjusted over the course of her next appointments.

Till today, Patient R continues to carry her medicines with her especially when travelling, although her itching and swelling are now under control.

Mistaken for eczema, allergies and insect bites

This frustration and multiple GP visits were shared by a 37-year-old male patient, who is referred to in this article as Patient D. He first spotted welts on his limbs and torso in June 2020.

Similarly, the 37-year-old first turned to over-the-counter antihistamines and even sought advice from his family.

Only after six months and three visits to his GP, did Patient D receive a referral to visit a dermatologist. Meanwhile, he struggled with disrupted sleep and had to reduce his participation in sports and social activities.

His fitness and social life also suffered, with him losing muscle mass as a result of the lack of exercise, and he drifted from his friends.

Even when Patient D was promptly diagnosed with CSU by the dermatologist in June 2021, he still did not understand much about this condition.

Dr Chiam weighs in: “CSU’s unpredictable nature, swelling and the often-long journey to get a proper diagnosis often lead to greater, more abrupt quality of life reduction than other skin conditions like atopic eczema. Most patients assume that CSU is due to allergies and will take great pains to avoid the triggers like foods and materials that they think cause the hives.”

She adds that the time to confirm diagnosis also ranges widely from weeks to one to two years, depending on the patient. “Referral to a dermatologist may take additional time, extending the period of suffering with uncertainty and ongoing symptoms like sleep deprivation.”

Presently, Patient D receives treatment focused on controlling symptoms and continues to follow up with the dermatologist annually.

Treating chronic hives

The first line treatment for CSU is non-sedating antihistamines taken regularly, not as and when there are flare-ups, says Dr Chiam. 

However, many patients remain symptomatic despite antihistamines. 

“In global studies, approximately half of all patients continue to experience symptoms even with treatment.

“For this group, alternative therapies are available. There are targeted treatments that are designed to act on specific parts of the immune pathway involved in CSU,” she adds.

Patients should see a GP if hives or swelling keep recurring for more than six weeks without a clear trigger. If symptoms persist, ask whether referral to a dermatologist is appropriate. 

Dr Chiam shares that patients can prepare for their visit to the doctor by taking photos of flare-ups, keeping a simple symptom timeline and making notes on how symptoms affect sleep, work or daily activities. 

“It is also helpful to describe the pattern clearly. For example, ‘This itchy rash appears at least four times a week.’ Naming the duration is key to raising suspicion of CSU. This helps doctors see the full picture and is the key trigger for diagnosis and treatment escalation,” she says.

Ultimately, the goal is to achieve greater public awareness, so people feel socially permitted to take symptoms seriously and speak up.

“By naming the condition and validating patient experiences, we can move from dismissal to understanding, and from repeated short-term fixes to more appropriate long-term management,” says Dr Chiam.

Patients ‘R’ and ‘D’ are composite profiles reflecting the lived experiences of people with CSU.

Find out more about chronic spontaneous urticaria (CSU) and how to manage it.