Alan Fletcher health: Neighbours star on his ‘serious’ condition – ‘I have a disorder’

Although not talking about what triggered the condition, the American Academy of Dermatology explains that alopecia develops when the immune system mistakenly attacks hair follicles causing inflammation.

Researchers believe that both genetic and environmental factors play a role in its development. It can begin at any age, with most people developing it during childhood or their teenage years.

The type that affects Fletcher, alopecia areata is the most common and refers to patchy baldness. It can affect anywhere on the body including the scalp, beard area, eyebrows, eyelashes, armpits and inside the nose or ears.

The other two most common types of alopecia include:

• Alopecia totalis: The person loses all hair on the scalp, so the scalp is completely bald
• Alopecia universalis: The person loses all hair, leaving the entire body hairless. This is rare.