KUALA LUMPUR, Sept 23 — In the middle of the night, an intensely itchy rash can suddenly spread across the body. It may disrupt sleep and leave a patient wondering what triggered it. Yet by the time the patient reaches a clinic, the rashes may already have disappeared.
“Normally, patients tell me, ‘Dr, the rash disappeared while I was waiting to see you, but from experience, I’m certain it will come back again,” said consultant dermatologist and vice president of the Dermatological Society of Malaysia Dr Peter Ch’ng.
“For many people living with Chronic Spontaneous Urticaria (CSU), this experience is all too familiar. Symptoms can come and go unpredictably, making them difficult to capture during a doctor’s appointment.
“Yet the impact of CSU often extends far beyond visible symptoms. Persistent itching and recurring flare-ups can disrupt sleep, affect daily activities, and take a toll on emotional well-being and quality of life.”
CSU is a skin condition involving recurring itchy, raised bumps, with or without deeper swelling known as angioedema, for more than six weeks without a clear external trigger.
As Dr Ch’ng explained, “The rash typically has a smooth, swollen surface, and each episode disappears within 24 hours, and new rashes emerge elsewhere.”
He stressed that patients often find this pattern disturbing because of its unpredictability.
Chronic urticaria affects approximately 1 per cent of the population worldwide. In a systematic review, pooled point prevalence in Asian studies was 1.4 per cent. This is roughly one in 71 people.
However, these estimates represent chronic urticaria overall and may include both CSU and CindU (chronic inducible urticaria), a form of urticaria triggered by specific external stimuli.
“Many patients know the rash only as gegata, the Cantonese term 风膜 (fung mok), or the Mandarin term 荨麻疹 (xún má zhěn). Others mistake it for eczema, psoriasis, or an allergy.
“Getting the diagnosis right matters because similar-looking conditions may require very different management,” Dr Ch’ng elaborated.
With haze conditions also raising health concerns, some people may wonder whether haze could trigger CSU. Dr Ch’ng clarified that haze has not been shown to directly trigger CSU.
“We know haze can trigger eczema, asthma, and allergic rhinitis. However, there is currently no evidence that it directly triggers CSU. Any potential relationship would likely be indirect, as stress could worsen urticaria3.”
For people experiencing recurring urticaria symptoms for six weeks or longer, useful clues include how the rash looks, how long each flare lasts, and whether it moves to different parts of the body. These patterns can help guide a proper medical assessment.
Dr Ch’ng shared the experience of a young patient whose CSU symptoms were not adequately controlled by antihistamines, the typical first-line treatment for CSU.
“He frequently had to miss classes, while his concentration and sleep were also affected,” Dr Ch’ng recalled. The condition disrupted both his studies and everyday life.
Dr Ch’ng said the experience also highlighted how difficult CSU can be for families to understand, particularly when the condition may appear to be “just a rash”.
“You will not understand unless you experience it yourself because the itchy rash can appear out of nowhere,” he said.
A recent Malaysian study similarly found that more than 80 per cent of patients with CSU reported moderate-to-severe itching and hives, which affected their work, social life, and daily functioning.
“Patients are constantly bracing for the next flare, and that uncertainty can create considerable anxiety,” Dr Ch’ng said.
“Some patients see a specialist early, while others do so only when initial treatment has not brought adequate relief. By the time they are assessed, the rash may have disappeared, making diagnosis more difficult.”
Photographs are therefore invaluable. Dr Ch’ng also advises patients to note whether the rash is raised or flat, whether it is smooth or rough, whether each flare disappears within 24 hours, whether it migrates, and whether it leaves pigmentation or bruise-like marks.
Not every bout of hives is CSU, which is why the duration or recurrence of symptoms is an important clue.
Typical urticaria rashes are smooth, transient, and fade within 24 hours without leaving marks. Persistent, scaly, painful, or bruise-like lesions may suggest another diagnosis and should be medically assessed.
Together, these details can give your doctor a clearer picture of symptoms that may no longer be visible during the consultation.
Dr Ch’ng highlighted that one common way patients try to manage CSU is by applying steroid cream wherever new hives appear. However, he cautioned that this does not address a rash that rapidly vanishes and migrates.
“Before the steroid cream is absorbed, the rash will likely have appeared on a different part of the body,” he said.
“Chasing the rash with steroid cream is not the answer. Patients need systemic treatment that works from within.”
He also warned against repeated steroid injections (systemic corticosteroids) as a long-term strategy.
“While the treatment may suppress the rash temporarily, repeated use can carry significant health risks. That is why steroids cannot be used as a long-term treatment for CSU,” he said.
International guidelines recommend a second-generation H1-antihistamine as first-line treatment. If symptoms remain uncontrolled, treatment should be escalated under medical supervision in accordance with the guideline algorithm.
Dr Ch’ng said specialist input is valuable because patients require appropriate monitoring and counseling.
“Patients want clear skin. It is not enough to say the condition has improved by 50% when they still do not know when it will worsen,” he said. “Clear, symptom-free skin is our target now.”
Ahead of World Urticaria Day on October 1, 2026, Malaysians with recurring hives are encouraged to seek medical help to improve their overall quality of life.
For those who suspect they may have CSU, Dr Ch’ng advises noting when symptoms begin, how long each flare lasts, whether the rash migrates or leaves marks, the treatments tried, and the impact on daily life. Any difficulty in breathing or swallowing should be treated as a medical emergency.
Malaysians experiencing recurring hives for six weeks or longer should speak to a health care professional. If symptoms remain uncontrolled, ask whether referral to a specialist may be appropriate.
Recurring hives are not something patients need to simply live with. Photograph flares, keep a record of symptoms and seek medical advice if symptoms persist.
As Dr Ch’ng puts it: “Get the right diagnosis and start the right treatment as early as possible.”
