SKIN diseases are no fun, particularly as they can be so visible.
No one need know that you are having mental health issues, hypertension, diabetes, or even cancer in the early stages, if you can still function pretty normally.
But with a skin disease, the ailment is out there for the world to see.
So, perhaps it is not so surprising that a recent study from the United States found that patients with psoriasis felt that they had a decreased quality of life similar to those with other chronic diseases like congestive heart failure, coronary heart disease, diabetes and breast cancer.
The study was conducted by University of California, San Francisco, Psoriasis and Skin Treatment Centre director Prof Dr John Koo, and his colleague Dr Tina Bhutani, and has been accepted for publication by the Journal of the American Academy of Dermatology.
Prof Koo was in town recently for the launch of a new drug for scalp psoriasis, Xamiol, a combination of calcipotriol and betamethasone dipropionate.
One of the most common skin diseases out there, psoriasis is a chronic, inflammatory condition that is estimated to affect around two to three per cent of people around the world.
It commonly presents with patches of thick, red skin with silvery-white pieces of skin flaking off them.
While it can affect any part of the skin, Prof Koo says that based on his experience, around one-third of patients first develop the condition on their scalp.
"Typically, the hairdresser notices the lesion on the patient - the plaques (thick, red skin) and skin flakes," he explains.
Senior consultant dermatologist and honorary medical advisor to the Malaysian Psoriasis Association Dr Steven Chow, who was also present at the launch, says that most local patients with scalp psoriasis tend to present with "dandruff", which is actually the dead pieces of skin flaking off the plaques.
In psoriasis, the body's skin cell growth rate is accelerated beyond normal, and results in too many new skin cells being produced. This in turn causes the rapid buildup of dead skin cells on the body, resulting in "dandruff".
Dr Chow explains that the condition that is rightfully called dandruff is actually a medical condition called seborrhoeic dermatitis.
What's the difference?
While both scalp psoriasis and seborrhoeic dermatitis look quite similar, they are treated differently, with scalp psoriasis requiring prescribed ointments and/or medication.
Other associated symptoms of scalp psoriasis include itchiness and/or skin irritation, which can lead to sleep disturbances, as well as embarrassment and a tendency to wear light-coloured shirts (to prevent the dandruff from being seen).
According to a study published in 1998 in the journal Dermatology, 57% of the patients surveyed said that scalp psoriasis is psychologically and socially distressing.
The most distressing symptoms reported were itching, scaling and visibility.
Says Prof Koo: "The itching and other discomfort is a very big embarrassment, and has a negative impact on the patient's self-esteem.
"I think there is one big misunderstanding about patients with skin disease.
"Lots of people who don't have skin disease feel that disabling conditions like heart disease or being unable to walk, have the worst impact on patients.
"But patients whose appearance are affected are much more impacted that those with disabling conditions."
He explains that the level of sympathy is higher for people with physical disabilities, whereas there is more social stigma and lack of sympathy given to those with diseases that affect their looks.
"I think we are all very invested in how we look - just look at the cosmetics industry," he says.
Another aspect of psoriasis Prof Koo pointed out was the link between the disease and components of the metabolic syndrome, like hyperlipidaemia (too much fat in the body), diabetes, high blood pressure and coronary artery disease.
He said that patients with psoriasis have been shown to have a higher risk of developing metabolic syndrome than healthy people.
He theorised that this might have something to do with the increased inflammatory processes that result in psoriasis in the first place.
While there is no cure for psoriasis, it can be treated and can disappear for long periods. The key thing, Prof Koo says, is to stick to the treatment regime your doctor prescribes and keep at it until the plaques are completely gone.