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Ask Dr Mark Porter

Dr Mark Porter

2 July 2021

Our health columnist, Dr Mark Porter, is one of the country’s best-known GPs.

Our expert on sun-damaged scalps, sex after a heart attack, constipation and cancer referrals.

Q.  I have spent a lot of time working outdoors and, thanks to losing my hair at an early age and never wearing a hat, now have a lot of sun damage over my bald patch. My GP says the crusty areas are actinic keratoses and has prescribed a cream. He warned me they could turn cancerous. Will the cream stop this?

A.  Actinic keratoses (AK) typically appear as raised rough, scaly or crusty areas on skin most exposed to the sun, such as the scalp in bald men, temples, face and tops of the ears. They are caused by UV-induced damage to the DNA in skin cells and can turn cancerous with time. The risk is small if you only have a few, but if you have ten or more there is around a one in 12 chance that one of them will turn into a squamous cell carcinoma (SCC), requiring more aggressive treatment. SCCs are not as serious as melanoma but have to be removed surgically or treated with powerful creams.

The damage has been done, but it’s not too late to prevent further complications. It is vital that you reduce your exposure to further UV, something all bald men should note. Wear a hat outside and/or cream with an SPF of 50. Vitamin B3 pills (500mg twice a day) are recommended by some dermatologists but the evidence that they help clear the lesions is not convincing. Treatments such as creams/gels or freezing (cryotherapy) can help improve your scalp but often must be repeated as the lesions recur, or new ones develop. Click here for more information on all the various treatments.

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Q.  My husband had a heart attack two months ago. Luckily, he was treated quickly and had a stent placed in his coronaries. How long should we wait before making love? He appears to have come through it unscathed and is back to his normal activities – walking and playing golf – but we are wary of resuming our sex life. Is it safe?

A.  I am pleased to hear your husband has recovered. People often worry about the link between sexual activity and heart attacks, but the risks are exaggerated. Heart attacks induced by making love are rare. In one American study fewer than 1% of all heart attacks occurred within an hour of sexual activity. Most were in men, many of whom had overindulged in food and alcohol before having sex, and/or were in an extra-marital relationship. Make of this what you will.

The physical exertion associated with (most) sexual practices – even among those in their twenties – is no more strenuous than walking up a moderate gradient. If your husband can play golf without symptoms such as chest pain, there is no reason why you should not resume your love life.

Q.  Is it safe to take the laxative macrogol long-term? I have been prone to constipation ever since I retired and have become less active. It is the only thing that keeps me regular, and I have been taking a sachet a day for nearly a decade.

A.  Macrogol works by keeping fluid in the stool (an osmotic laxative) and is one of the safest types for long-term use. And one sachet a day is a lowish dose.

The key question is, what do you mean by regular? If you are passing a motion at least three times a week, don’t strain excessively when you do, and have a healthy intestinal transit time (the number of hours food takes to travel through you), then you are normal and do not need to take a laxative. Don’t get too concerned about going every day, as many people do.

You can work out your intestinal transit time by eating a bowl of sweetcorn and checking when it comes through the other end. If your bowel is working properly the bulk of it should pass through over the next 18-48 hours (in some people, it can take even longer but still be normal).

If you are on the slow side, switching to a high-fibre diet that includes plenty of fruit, vegetables and wholemeal cereals, and drinking plenty of fluids, might be just as effective as the macrogol. You should boost your activity levels, too, because a sedentary lifestyle encourages constipation, as you have discovered since retiring.

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Q.  I have had some difficulties swallowing over the past few months – it felt like food was getting stuck– so I consulted my GP. She told me the symptoms were worrying and I have been referred on to the suspected cancer pathway (a ‘two-week referral’). I am now panicking. I realise you can’t say what they are going to find in my case, but what proportion of people with my symptoms turn out to have cancer?

A.  Difficulty swallowing is an important symptom that should never be ignored. Since your initial email you have been investigated and I am pleased to report that you have been given the all clear. It turned out to be a benign tightening (stricture) in your gullet.

However, I still wanted to publish your query because your predicament is a common one. More than two million people a year find themselves on the suspected cancer pathway, and they all worry.

The two-week referral system was established in England 20 years ago, and it does what it says on the tin. If you present to your GP with a worrying symptom (anything from rectal bleeding to a lump in your breast), and you/your symptoms fit specific criteria, then you should be seen by a specialist within two weeks to rule out an underlying cancer.

I tell anyone I refer that, although I may suspect the worst, it is still unlikely. Overall, fewer than one in ten people on the pathway in 2019 turned out to have cancer (6.6%), meaning at least nine out of ten (93.4%) didn’t. For more information on referral pathways across the rest of the UK, visit

Email or write to Dr Mark Porter at Saga Magazine, Enbrook Park, Folkestone, Kent CT20 3SE. He can’t reply individually but will respond to queries in Saga Magazine. Always talk to your own GP.

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Article first published in Saga Magazine July 2021.

The opinions expressed are those of the author and are not held by Saga unless specifically stated. The material is for general information only and does not constitute investment, tax, legal, medical or other form of advice. You should not rely on this information to make (or refrain from making) any decisions. Always obtain independent, professional advice for your own particular situation.