It all started on holiday. Or just after I got home to be more exact. After 10 days scuba-diving in the Caribbean I started to experience some very strange phenomena. First came the blisters on the hands, initially along the border of the thumb and forefinger. I noticed these while waiting at Tobago airport, but during the long flight home they blossomed into tense, split-pea-sized lesions, just begging to be popped. I put it down to having handled some coral the previous day, but less easy to explain was the throbbing, tense swelling of my thumb and big toenails.
Over the next few days collections of fluid appeared under most of my nails - on both hands and feet. And within a fortnight six of my toenails and my right thumbnail were in the bin. This time I blamed some ill-fitting scuba fins; not as daft as it sounds - downhill skiers often lose toenails due to repeated mild buffeting of the toes. The thumb was a bit trickier to explain, though.
Meanwhile the blisters on the hands were getting worse, and new ones were appearing daily. They would last for a few days before bursting to leave a bloody, crusted scab that took about a fortnight to heal properly. I had the same sort of lesions appearing around my face and neck too, and at this stage decided to see a dermatologist.
If this were a medical student viva examination, we would probably be getting to the Rolf Harris "Can you guess what it is yet?" stage in the proceedings. Only it seems a bit harsh to ask right now, as I am a doctor myself, and even with my intimate acquaintance of the signs and symptoms, I hadn't a clue. I make no apologies for bypassing the normal GP referral and popping round to the skin department. With my epidermis in its various forms shedding like that of a snake, I was scared, as well as clueless.
As with many skin conditions, it was the distribution that gave it away. All my problems were in sun-exposed areas - face, hands and feet (I had spent most of the holiday barefoot). It took the skin doctor just one look to reach a diagnosis. He thought I had porphyria. And he was right.
There are worse diagnoses to get, of course, but it still gave me a bit of a fright. Porphyria is one of those diseases you read about in textbooks - usually accompanied by frightening photos and stories of werewolves. It's the sort of thing that makes for an interesting discussion on the pathogenetic biochemistry involved, not something that you want to take home with you afterwards. But a couple of weeks later, the result of my 24-hour urine collection came back from the special porphyria lab in Cardiff. Normal people are allowed up to 600 units of the little light-sensitive molecule they measure in every litre of their pee. I had over 11,000.
There are many forms of porphyria, some congenital and some acquired in adult life. Mine - porphyria cutanea tarda, or PCT - is one of the milder, acquired types. The porphyrins are a family of molecules produced from red blood cells gone past their use-by date. The red pigment, haemoglobin, is metabolised in the liver and normally ends up as yellow or brown pigment, giving urine and faeces their characteristic colours. But if for whatever reason the liver cannot complete this reaction, levels of intermediate byproducts including porphyrins accumulate in the body.
Let's get the slightly embarrassing part out of the way. The reason I had developed PCT was that I was drinking too much alcohol. Not Oliver Reed or George Best proportions, you understand, although I can recommend sticking a recent picture of Bestie on the fridge as an excellent aid to abstinence. The actual amount is not that important, but it was too much for my liver to handle comfortably. It was so busy trying to cope with the booze that it had somewhat neglected its duties on the haem pigment metabolism front.
The more I learned about PCT, the more things began to fall into place. I had noticed for some time that my urine was a strange colour - more like Coca-Cola than apple juice. This was the porphyrin pigments. For months - even before the holiday - people had told me how tanned and healthy I was. Not suntan, of course; the porphyrins again, this time deposited in the skin. I had started having to shave my face in strange places too. Close up, it was apparent that my eyebrows were merging into my beard. Facial hypertrichosis, or excess facial hair, is another symptom of porphyria. And the main thing people with PCT cannot do is go out in the sunshine; hence the supposed connection with hairy-faced werewolf myths.
You could write a very thick book on porphyrin metabolism, as indeed someone has. The more serious, congenital forms of porphyria can be fatal, and lead to widespread damage to many organ systems including the brain. King Gorge III has famously had his madness blamed by some on familial porphyria.
The type of porphyria I have is relatively benign, unless you encounter ultraviolet light. This causes a chemical change in the particular porphyrin involved, and turns it into a chemical that is especially toxic to skin, breaking down the bonds that normally hold skin cells together. It splits the layer of skin it is lying in, causing blisters, scabs, and eventually intact, but incredibly fragile skin, especially over the backs of the hands. For a time even putting my hand into the pocket of a pair of jeans was enough to rip a painful strip of skin off my knuckles, leaving it raw and bleeding. When the area exposed to UV light is the bed of a finger or toenail instead, photo-onycholysis occurs (the posh term for loss of a nail due to light exposure).
With the diagnosis established, next came what to do about it. There are a few fancy treatments for stubborn cases, but the initial mainstay is to rest your liver and give it a chance to repair itself. Thankfully, I was able to stop drinking without so much as a flicker of the DT's, and my liver cells have been freed up to do other things. I've stopped looking so unnaturally brown, my urine is a lovely pale yellow colour once again, my nails have grown back and I can almost put my hand in my pocket without fear it will come out looking like something from a Stephen King movie. But for quite a while yet I will still have to avoid both alcohol and sunshine, which will make for rather dull holidays.