Fans of Hong Kong actor Wong He were left stunned by photos of him with a bloody nose and face mask posted on social media. He wrote on his Facebook page on April 3 that he was “stabbed” in the nose during a polymerase chain reaction (PCR) test on his arrival in Taiwan. “The assailant has since left the scene. Of those who are left behind, no one knows the assailant’s name, all they know is that she came from the hospital,” he wrote. Best known for playing a firefighter in TVB’s Burning Flame series (1998 to 2009), Wong had landed at Taoyuan International Airport, where all travellers must have a Covid-19 PCR test on arrival. According to the actor, the medical professional who gave him the swab test used her right hand to push the cotton swab into his nostril while using her left hand to push the back of his head forward. When he recoiled in pain, he said she asked him to put up with it and assured him that she wouldn’t hurt him. When she inserted the swab again, Wong’s right nostril started bleeding. Then she left. Other staff offered Wong assistance but he refused it, he wrote on Facebook, because he was not satisfied with the rolled toilet paper given to him to stop the nosebleed. Later, he shared that he had tested positive for Covid-19 and was sent to a quarantine facility. He filmed himself taking a rapid test the day after, which was negative. Nasal swab test nosebleeds ‘rare’ Don’t let the sight of Wong’s bloody nose put you off having PCR tests or self-administered rapid antigen tests – nasal swab tests rarely result in nosebleeds, says Dr Winnie Chui, a Hong Kong specialist in family medicine. They can happen, though, especially if someone has a pre-existing condition, such as a deviated septum where the thin wall, or septum, between the nasal passages is off centre. “If you don’t know about that person’s medical history, then obviously, if you insert the swab too deeply, then that can traumatise your septum,” Chui says. In Wong’s case, it’s possible that his nostril was traumatised simply because it was poked too deeply and quickly at the same time. Not to be sniffed at: amazing facts about the human nose Professionals performing PCR or rapid antigen tests (RAT) are trained to insert swabs close to the back of the nose, but there shouldn’t be an issue if the swabbing is performed gently, according to Chui. “When we put the swab in there, we feel the resistance, and we stop when we feel there’s resistance. But if you just do it too quickly, and you don’t feel it, then obviously you can traumatise someone’s nose,” she says. If a nosebleed does occur after a test, and there are no related pre-existing conditions, Chui recommends treating it like a regular nosebleed. Don’t panic; sit up straight or lean forwards – do not lean backwards; breathe through your mouth, and use your thumb and index finger to pinch the soft portion of your nose near the front for at least five minutes before checking to see if the bleeding has stopped. If it has not, hold again for another five to 10 minutes. If the bleeding hasn’t stopped after 15 minutes, apply an ice pack or cold compress to the bridge of your nose, which can constrict the blood vessels and help bring the blood flow to a stop. Performing rapid self-tests safely and effectively Chief Executive Carrie Lam Cheng Yuet-ngor has urged Hong Kong residents to self-test from April 8 to 10 using rapid self-test kits, but there’s no need to be nervous about hurting yourself while doing the test if you follow the instructions properly. Covid test kits to be used to confirm Hong Kong cases. But how accurate are they? Because the technique required differs from brand to brand, read and follow the instructions carefully, Chui says. Generally, the tests direct you to insert the swab into your nose and swirl it against the wall of both nostrils before putting the swab tip into a buffer solution. To avoid errors, at least five swirls should be done in each nostril. When squeezing droplets of solution onto the test panel or cassette, Chui warns not to overfill it, as too many drops could contaminate the test. If test results are inconclusive – such as if a solid line appears next to the T (which indicates a positive test) but not the C, or if there is a faint line next to the T and a solid line next to the C – then she recommends repeating the test, possibly using a different brand. Green light for 12 rapid antigen tests as China races to beat Omicron surge Inconclusive results could indicate that you have the virus and it is still in the incubation period or you have largely recovered, for example. It could also be a false positive or an indicator that you will test positive on a subsequent test. “The reason why we don’t swab the throat instead with these kinds of test kits is just that it causes gag reflex and [it’s not a] very comfortable thing. In general, it’s just easier to do the nasal swab,” Chui says. However, if someone has a deviated septum, they can use the swabs to take a throat sample instead. Refrain from eating or drinking for 30 minutes to an hour before taking a throat sample to avoid contaminating the test. Chui has a final tip for self-swabbers doing a nasal test to increase its sensitivity: “Sneeze a little bit just to get a little bit more of the nasal discharge to the front of your nose.” If there’s enough mucus towards the front, then you may not have to insert the swab as far back. Some patients are more sensitive in the nasal area than others, but generally everyone has been able to tolerate the tests. “Sneezing afterwards [comes] naturally, that’s just what happens,” Chui says. “If you are very anxious about doing it yourself, maybe get a family member or a friend to help you.” Like what you read? Follow SCMP Lifestyle on Facebook , Twitter and Instagram . You can also sign up for our eNewsletter here .