Alan Fletcher, who plays Karl Kennedy in Neighbours, first appeared in the show in 1994 and is the soap’s third longest-running character.
His character is well-known for a 1990s storyline in which he had an affair with his wife’s best friend. The actor took to social media to explain his character’s sudden hair loss in the show after some fans expressed concern for the actor’s health.
But what has caused it and what did Alan say about it? Here’s what you need to know.
Why is Alan Fletcher wearing a hat?
The 65-year-old told his followers on social media that he lost his trademark grey hair and stubble due to a battle with alopecia areata, which he said caused patchy hair loss.
He wrote on Instagram in May: "There’s been concern expressed on the web that I am unwell. I can assure you I am fit and well and very busy filming the last episodes of Neighbours EVER!
"I have a disorder called alopecia areata that causes patchy hair loss. I have recorded a video explaining the condition which you can view on my website and on the Neighbours Facebook page.
"Thank you for your concern and support. Fletch."
In a video uploaded to Neighbours’ official Twitter, the actor removed his hat to show his new look.
Fletcher said: "I shaved my beard off, and then my hair became so patchy on my head I had to get rid of most of that as well.”
"I have no problem with it, in fact, it’s kind of fun,” he added.
"But one thing I will say is that alopecia areata can be quite serious to people, particularly from an emotional point of view. Sudden hair loss is really troubling for a lot of people, particularly for young people who can be terribly bullied. There is support out there.
"But let me assure you I’m absolutely fit and well and thank you for your concern."
The final episode of Neighbours aired in the UK on Channel 5 on Friday 29 July at 9pm. But Neighbours fans will be pleased to hear the show is returning in 2023 on Amazon Freevee.
What is alopecia areata?
Alopecia areata is a common autoimmune disorder that often results in unpredictable hair loss.
What are the symptoms?
The most prominent symptom of alopecia areata is patchy hair loss.
Coin-sized patches of hair begin to fall out, mainly from the scalp, and any site of hair growth may be affected, including the beard and eyelashes.
The loss of hair can be sudden and can develop in just a few days or over a period of a few weeks.
There may be itching or burning in the area before hair loss.
However, the hair follicles are not destroyed so hair can regrow if the inflammation of the follicles subsides.
If there is a complete loss of hair on the scalp, doctors usually diagnose alopecia totalis and if there is hair loss throughout the entire body, the condition is called alopecia universalis.
Alopecia can affect anyone, but most cases develop before the age of 30, according to MedicalNewsToday.