The urge creeps up on me as I lie in bed, just before lights out. It’s akin to an itch, a playful little niggle. ‘Go on,’ it says. ‘A quick one won’t hurt.’

I put down my book and quietly reach for my phone, keeping my movements slow and subtle so I won’t wake my husband. I’ll then artfully angle the screen away, pull the duvet over my head, put in my earpods and surrender myself to pleasure.

What will it be tonight, I think as I begin scrolling through my secret stash of online treats, my pulse quickening.

‘You do realise I can see you,’ my husband says, wearily. ‘I know exactly what you’re up to. You’re sick in the head.’ Damn, rumbled again.

A bit harsh, yes, but then that’s the reaction of most people when I confess my bizarre little fetish: aged 58, I like to unwind by watching videos of blackheads being extracted, callouses and corns being dug out by podiatrists and occasionally, depending on how hardcore I’m feeling, the removal of a badly infected in-grown toenail.

I absolutely love them – they’re my equivalent of crochet or popping bubble wrap. For me, there’s no stress that can’t be defused by the sight of a good chunky verruca being triumphantly brandished on the end of a scalpel.

I know, at this point, squeamish readers will be recoiling in revulsion, but I’m by no means niche; there are millions of us out there eagerly watching this material every day.

Our high priestess of grossness is the legendary Dr Sandra Lee, aka Dr Pimple Popper, a Los Angeles-based dermatologist, who started posting videos of her procedures on her YouTube channel ten years ago, affording some respectability to the fetish, and bringing it into the mainstream.

Julia Lawrence likes to unwind by watching videos of blackheads being extracted and callouses and corns being dug out by podiatrists

With a combined 30.5 million followers she now has cult-like status, with her videos having been viewed billions of times, and has even had her own TV programme (with lots of trigger warnings to protect the wimps).

She’s inspired scores of imitators who address various medical ailments – another favourite of mine is Shanti McGinley, and her oddly named brand, Parmesan Palms, which has 1.4 million followers on TikTok.

Speaking in a beautifully mellifluous voice, she posts videos of her dealing with a rare genetic disorder called diffuse epidermolytic palmoplantar keratoderma, a condition, which she shares with her son, that causes her to produce excess amounts of keratin in the skin of her hands and feet.

She deals with this by clipping, shaving and grating it off in videos which, for me, are simply divine. Don’t believe me? One of her videos has been watched 53.8 million times.

But why do I and fans like me find these videos so addictive, and others find them so repulsive? It’s a fascinating question that has prompted legitimate academic research.

A study, published in the in the scientific journal Behavioural Brain Research in 2021, used a neuroscientific technique called functional magnetic resonance imaging to scan the brains of 80 volunteers as they watched pimple-popping videos.

The results found those with a low squeamishness threshold, like me, got a dopamine hit from the videos, and a sense of stress-relief and catharsis. For us, these videos provide an outlet for a thrilling, yet safe experience of disgust known as ‘benign masochism’.

Personally, I blame my mother (don’t we always). I grew up in Clacton-on-Sea, Essex, where she was a nurse at the local GP practice, and back in the Seventies, before I started school, she sometimes had to take me with her in the absence of childcare.

Dr Sandra Lee performs surgery to remove ketoids (irregular fibrous tissue) on a patient’s ears

I’d be quite happy playing with my dolls under the consultation couch, and occasionally I would pop my head out to see what was going on.

Apparently, I’d be utterly transfixed by the sight of Mum applying liquid nitrogen to a plantar wart on someone’s foot – I can still hear that sumptuous hiss and crackle – and would beg for a chair so I could climb up for a prime view of a bothersome lump of wax being removed from someone’s ear.

My best friend, Bea, 57, is a fellow enthusiast. We have our own WhatsApp group where we share good videos we’ve found. My 28-year-old daughter Lois is now a member and introduced me to the joy of acid peel pedicure videos (a procedure where feet are soaked in acid, then the hard skin is peeled away in strips).

Still, there is a feeling of being part of an underground, clandestine group. I have to be careful where I choose to indulge my fetish. Public transport is a definite no-no, judging by the look I once received from a fellow passenger as I enjoyed a good in-growing hair video on my commute home.

I felt like it would have been less shameful being caught watching porn.

But each to their own. I urge you, the next time life feels like it’s getting too much, to put down your wine glass, pick up your phone and join us. You won’t be disappointed.