This is a rash where the skin becomes inflamed, appearing on greasy areas with lots of sebaceous glands - on the cheeks, between eyebrows, the folds next to the nose and the chin, and also on the chest or scalp. Red, greasy, scaly or flaky patches are common and little red bumps known as papules may appear. It can cause a mild itch but it's that appearance prompts most sufferers to seek treatment. It is considered to be a type of eczema, but can also overlap with psoriasis and rosacea. Stress, tiredness and cold weather can prompt flare-ups in those susceptible. An overgrowth of a usually harmless yeast (posh name: Malassezia) is thought to be part of the cause, so treatment focuses on eradicating this and dampening down inflammation using a combined anti-fungal and mild steroid cream.
No, this is not contagious to others.
The mainstay of treatments available at the pharmacy for seborrhoeic dermatitis are moisturisers to reduce the dry flaky patches. Treating the scalp and hairy areas is best using an oil or liquid-based treatment rather than a cream, as it is easier to apply. Coconut oil is a fantastic moisturiser that also has some mild antifungal properties due to it containing caprylic acid. Applying it 2 - 3 times a week to the scalp or an hour before bathing will help to ensure a healthy environment for the scalp with regards to pH levels and moisture. There are some shampoos such as 'Selsun' (containing selenium sulphide) which is also effective in adults, or coal tar based 'Alphosyl' which contains an anti-scaling agent in the form of coal tar extract. For children suffering from cradle cap or those with sensitive skin 'Dentinox' cradle cap shampoo is also a milder alternative.
You are likely to be fit for work.
You can buy treatments from your pharmacy - if you are sure of the diagnosis, it is worth trying these before seeing your doctor. Depending on how bothersome your symptoms are, you can request this as routine or urgent.