I’m a fit 78-year-old but, since having sex aged 23, I’ve experienced very strong, painful itching in my genitalia. Specialist tests found nothing wrong. I’ve put up with this intense itching inside the tip of my penis ever since. Recent tests failed to find any signs of STI or other disease. It has caused me considerable distress and I’m desperate to rid myself of this suffering.
Name and address withheld.

Chronic persistent itching can be triggered by psychological factors and changes in the way the brain responds to the sensation of itching
Dr Martin Scurr replies: Firstly, I want to assure you that, although this complaint extends back 55 years, it’s not a hopeless case: it’s also something many men suffer from.
It seems that despite repeated, thorough investigations, no infection has ever been identified as the cause. And examining your longer letter, I believe your problem has a different cause: psychogenic pruritus.
This is where chronic persistent itching is triggered by psychological factors and changes in the way the brain responds to the sensation of itching.
The brain plays a crucial role in the perception of an itch – and research where people with psychogenic pruritus underwent MRI scans revealed changes in activity in the areas of the brain concerned with processing itching sensations.
I think you may initially have had a minor itchy skin condition, probably thrush.
Your painful and potentially guilt-inducing experience at the clinic, coupled with being told you didn’t have an infection, was then the trigger for a form of post-traumatic stress.
This could have become a psychological driver for perpetuating the itch ever since.
The good news is that this can be remedied. I urge you to discuss this potential diagnosis with your GP and ask to be referred to a clinical psychologist who will offer cognitive behavioural therapy.
You may also be prescribed a low-dose antidepressant or a gabapentin – drugs that help with this kind of symptom.
If you can accept this change of direction, and if you are given the appropriate referral, you could be cured within months.
My partner has lost more than a stone, which he didn’t need to lose and can’t be explained. He’s had blood tests but the only one that was abnormal was for LDH levels. He was referred and had a CT scan, but all is apparently fine. Should I feel assured that he is OK?
Lisa Henderson, by email.
Dr Scurr replies: LDH (lactate dehydrogenase) is an enzyme found in the fluid in nearly all cells.
It only appears in the bloodstream if cells are damaged or destroyed – for instance, due to ischaemia, where blood supply is cut off in tissues such as the intestine or muscle tissue.
However, there would almost invariably be other symptoms, so since your partner appears to have no other signs, this seems less likely.
The same applies with other causes of raised LDH, serious infections such as tuberculosis or even glandular fever. LDH may also be released from liver cells (and the levels of the other liver enzymes may be fine), as a result of one of a number of different liver conditions.
Levels may also rise as a result of cancer, before any other markers are seen on blood tests.
I would suggest asking your partner’s GP to refer him to a Rapid Diagnostic Centre for review, which might include weighing him regularly (over a period of four to six weeks, for instance), scanning him again and offering further blood tests. There should also be checks for occult (i.e. ‘hidden’) infections, which will involve sophisticated tests.
In the meantime, weigh him once each week at home (at the same time of day) and keep a careful record.
In my view he should be reviewed within three months after the last CT scan.