As you might well know by now, there’s a difference between dry and dehydrated skin, but if you need a quick recap, dry skin is caused by a lack of oil in the skin and is a skin type, whereas dehydrated skin is caused by a lack of water and is a skin condition.

While there might be a bit of a crossover in how dry and dehydrated skin present, if you suffer from either, skin is likely to feel tight and may look dull or inflamed.

Dr Uliana Gout of London Aesthetic Medical and Etre Vous Editorial Panel member explains that dry skin is likely to be characterised by “scaly cracking skin which can also feel itchy and rather uncomfortable.”

What causes dry skin?

“Some people have naturally dry skin—there may be a genetic component—and it’s also something that is more likely in older people as our pores produce less oil with age,” explains Dr Gout.

“But it’s also caused—or exacerbated—by a variety of factors. The weather— and specifically the low humidity levels present during the autumn and winter (while you might think that the weather is less humid when it’s hot, because cooler air holds less moisturiser, it tends to be the colder months that are less humid), chemicals that we may encounter in everyday life, and even hot water can all result in dry skin, or make dry skin worse.”

Conditions, such as contact dermatitis, seborrhoeic dermatitis, atopic dermatitis, psoriasis and eczema can also result in dry skin.

“In some cases dry skin can be chronic—something that is with you for life—and needs management with maintenance programmes, and in others it can be aggravated and therefore with the right approach it can be treated,” says Dr Gout.

How do you treat dry skin?

Dry skin lacks oil and so you need to use skincare products that will help to provide it with the ingredients it’s missing.

In healthy skin, lipids and ceramides are two of the fat-based molecules that help to keep the skin barrier healthy—essential for protecting the body from infection—and the skin looking smooth, so look out for creams that contain these types of ingredients.

It’s also worth adapting your usual regimes to ensure that you’re not making the problem worse. So, for example, Dr Gout recommends using moisturising soaps and cleansers to her patients with dry skin, and—in extreme cases—some dermatologists advocate using soap alternatives, such as E45 Emollient Wash Cream and Aquamax Wash which are free from the fragrances and detergents that can further dry and irritate skin.

And applying your moisturisers sooner rather than later is essential. “I like to recommend my patients moisturise their skin right after washing or cleansing,” says Dr Gout.

Just how dry your skin is will dictate exactly what you use to moisturise. Moisturisers tend to be a mix of oils and water—the drier your skin is, the more oil you'll want to use. Lotions have the lowest concentration of oils, creams have more, whereas ointments tend to be exclusively oil-based.

“Extremely dry and uncomfortable skin can be treated with a petrolatum-based product,” advises Dr Gout.

She also recommends a humidifier, especially during the dryer autumn and winter months, as this can make skin feel more comfortable.

Are there any skincare ingredients I should avoid?

Because dry skin has less oil in it, and can—as a result—be accompanied by a damaged skin barrier, Dr Gout advises avoiding any ingredients that could aggravate the skin—such as strong chemical exfoliants, like glycolic acid, or retinoids.

That’s not to say that you can’t ever exfoliate or use retinoids. A gentle exfoliant, such as lactic acid, can help to carefully slough off flakes without further damaging skin.

A dermatologist can put together a topical skincare regime to help you rebuild your skin barrier, and once it's strong enough, give you appropriate retinoid products which will give you their benefits without further irritating your skin.

Can in-clinic treatments help dry skin?

Most of the treatments offered in clinics that help "dry" skin are actually for dehydrated skin and so tend to focus on hydration—getting more water into the skin—rather than emollients, putting more oil onto the skin.

But if you suffer from dry skin, ensuring you don’t make things even worse by also having dehydrated skin, is a sensible approach.

As such, look out for deeply hydrating facials, but also treatments such as Profhilo which involves injecting hyaluronic acid—something that naturally occurs in the skin and acts like a sponge, holding a lot of water—that can help to ensure you don’t have to deal with the double whammy of dry and dehydrated skin.