The scenario

Linda McKay has come into the pharmacy and smiles, then winces, when she sees pharmacy technician Vicky at the counter.

“I’m wondering if you can help me,” Linda starts. “I’ve got this little spot or cut at the side of my mouth, and it’s driving me crazy!”

“How long has it been there?” asks Vicky, leaning over the counter for a closer look.

“A few days,” replies Linda. “It’s right in the corner, so every time I open my mouth wide – if I eat or smile, basically – I can feel it crack open again. I know it looks tiny, but honestly, it’s really quite painful.”

“Have you had anything like this before?” queries Vicky. “And have you tried anything for it? You don’t take anything other than those vitamin D tablets we dispense for you, do you? I take it nobody else in your family has got the same thing?”

“Nope, it’s just the vitamin D I’m on and it’s just me that seems to have it,” says Linda. “I’ve tried a lip balm for this, but it isn’t really doing anything. I had the same thing a couple of months ago, and I don’t really remember what helped it go. Someone said that it might be a sign I’m low in vitamin C – do you think that could be the case?”