Q .I am a 28-year-old man and I am very active in sports.

In the last two months, I had a sudden onset of skin rash on my face and body, especially on my hands and arms, something which I have not had before.

It is quite alarming as the rashes are red and blotchy.

I am not on medication and I have been careful with my diet.

I have tried applying over- the-counter medication but none of it seems to help.

What is happening and what can I do?

A. There are a few possibilities for the cause of your rash.

You do not mention if the rashes are itchy, and whether they are persistent or transient but recurrent.

Given the fact that you are otherwise healthy and not on any long-term medications, you may have the following conditions:

•Dermatitis/eczema: The terms dermatitis and eczema refer to the same condition. It is due to inflammation of the skin and has many causes, and it occurs in different forms.

The skin may be oozy, dry and flaky, or even thickened, depending on the condition.

It is itchy and can be aggravated by exposure to the sun, in some cases.

Some common types of dermatitis include atopic dermatitis, which usually begins in childhood and can affect the face and arms, as well as the folds of the skin. It is a chronic condition which can flare up from time to time.

Contact dermatitis can occur if there is a substance in contact with the skin that causes irritation or an allergic reaction, including products such as perfumes, hair dye or even some creams and lotions.

Dermatitis is not contagious and is usually treated with topical medications.

A patch test can be ordered if the doctor suspects contact dermatitis.

• Urticaria: This is also commonly referred to as hives.

It is an itchy condition that usually starts as an itchy patch of skin that then develops into red welts, resembling a mosquito bite.

The itch can be mild to severe, and it can be triggered by many substances or situations.

There is a particular form of urticaria that is triggered by heat and exercise, known as cholinergic urticaria.

The rashes can last from a few minutes to hours, but should resolve within 24 hours. It can then recur, sometimes on a daily basis.

• Pityriasis versicolor: This is a type of superficial fungal infection. It causes a fine, scaly rash that can become extensive if it is not treated.

It is caused by a yeast that lives normally on our skin.

The infection can occur in some people because of oily skin, living in a hot and humid climate, or in people who sweat a lot.

It is not contagious and can be treated effectively with both topical and oral anti-fungal medications.

I would advise you to seek medical attention regarding your skin rash as you have tried self-medication without success.

You should also see a doctor if you become so uncomfortable that you are losing sleep or are distracted from your daily routines, or if you suspect that you have a skin infection.

Dr Tan Hiok Hee
Senior consultant dermatologist at Thomson Specialist Skin Centre