Practice in pictures:Eczema

Eczema is a frequently presenting condition in primary care. It is is an inflammatory skin condition, which may be induced by a wide range of external and internal factors, singly or together.¹ The terms eczema and dermatitis are generally used interchangeably. Eczema is often seen in people who have an ‘atopic tendency’ – which means they may also have or develop any or all three of the closely linked conditions, eczema, asthma and hay fever.¹ Current thinking is that a genetically-linked primary defect in the skin barrier is an underlying cause, reinforcing the importance of the regular use of emollients to assist management.¹

ATOPIC ECZEMA IN A BABY

This is one of the most common problems that we see in young babies and children. It affects up to one in five children in the UK. It may develop at any age throughout life, but in babies can be seen quite soon after birth. The atopic part of the name refers to the link with other atopic conditions, including asthma and hay fever. Eczema derives its name the Greek word ‘to boil’ referring to the red, dry itchy skin that characterises the condition. It is a multifactorial condition with a strong genetic predisposition upon which environmental factors may be the trigger leading to manifestation or deterioration of symptoms. The primary symptom is itching. This can be extremely distressing and causes a range of problems both in the skin and systemically. The condition cannot be cured but must be managed. It is possible to significantly reduce the chance of babies developing eczema by the use of an appropriate emollient, for example 50:50 liquid and white soft paraffin, regularly from birth. On going management of the skin of affected babies is a time consuming and difficult task, requiring devotion from parents and support from health professionals. Emollients to protect the skin barrier are the mainstay, and they need to be used in adequate quantities. Using insufficient emollient is a common error leading to breakthrough attacks.

INFECTED ECZEMA

Patients who have atopic eczema or dermatitis will be aware of the basic principles of management of their eczema. This includes frequent regular and adequate use of emollients and the avoidance of irritants that trigger or exacerbate their eczema. They may ‘follow the rules’ but still find that during flare ups, their eczema does not respond to the normal treatments that usually work. This will often include an escalating series of increasingly potent topical corticosteroids. One reason is that the eczema becomes chronically infected due to a breakdown of the normal protective mechanisms present in the skin that stops organisms such as staphylococci or streptococci. These bacteria are widely present in our environment and don’t usually cause infections. However, here the skin has become increasingly inflamed and broken, leading to infection and this crusting, which is relatively uncommon. Infected eczema rarely looks this obvious: slight weeping is more common. Oral antibiotics will almost certainly be needed to supplement the other treatments being used.

CONTACT DERMATITIS

This type of eczema is also common and is usually fairly easy to diagnose. Contact dermatitis can be split into two broad groups: allergic contact dermatitis to metals, cosmetics, latex, and irritant contact dermatitis to various chemicals such as detergents, bleach and adhesives. The diagnosis is most often made as a result of careful history and assessment of the site at which the eczema is manifest. For example, one of the commonest metals to cause contact dermatitis is nickel, and this may be found in belt buckles, with a very obvious patch of dermatitis around the contact patch on the anterior abdominal wall. Other allergens may be harder to identify, and further investigation and testing may be required. Patch testing in secondary care is probably the best way of confirming the diagnosis where some of the more difficult cases occur. This is important as the mainstay of treatment here is clearly avoidance, and knowing exactly which allergens are involved is crucial when trying to navigate through the small print of a list of ingredients in a cosmetic product for example.

VARICOSE ECZEMA

This type of eczema is also known as gravitational or stasis eczema. It is very common in our older patients, especially females and obese patients. It is caused by incompetent valves in the leg veins, most often due to varicose veins, which do not necessarily have to be huge contorted vessels. This leads to downward pressure in the lower part of the legs. This in turn causes fluid to leak out of the veins and into the tissues, where the eczema is then characterised by the same changes as seen elsewhere, with redness, dryness and irritation. The breakdown of blood cells in the tissues leads to the characteristic brownish discolouration due to deposition of haemosiderin. The management of this type of eczema again centres on the basics of using emollients to moisturise the skin. Topical steroids are frequently used, but need to be prescribed and applied carefully to avoid overuse. Elevation to reduce the pressure may help, and most patients should have an ankle brachial pressure index (ABPI) measurement undertaken to assess the need for compression. This may be very helpful in the management of secondary ulcers, which are a frequently seen complication leading to a huge strain on primary care resources.

POMPHOLYX

Pompholyx or dyhidrosis is a form of eczema that affects a different part of the body than ‘regular’ eczema, which is usually seen in skin flexures. As seen here, pompholyx affects the palms and soles of the feet. It tends to be quite itchy, and often presents with small blisters containing clear fluid. The roof of these blisters is quite thick and doesn’t always burst, though it can sometimes, and then may develop a secondary infection. Pompholyx tends to occur in younger adults below the age of 40, and may be triggered by a range of possibilities including excessive sweating, and fungal infections.

If possible, the blisters should be left, as de-roofing them may expose very sensitive skin. Management involves emollients and potent topical steroids – the steroid may well need to be more potent due to the thickness of the skin. Potassium permanganate soaks, and antihistamines may also be used and the course of the condition can vary significantly from a single acute episode to a long-standing chronic course. Very occasionally, phototherapy and immunosuppression may be used.

SEBORRHEIC DERMATITIS

This is a variation on eczema that primarily affects areas of the skin which are greasy and contain lots of sebaceous glands. These areas include the scalp and nose (as seen in this picture).

It may manifest in very young babies as cradle cap, or appear later. The type of symptoms seen are associated with the skin areas and consist of essentially increased greasiness of the skin with thickened scaling skin which may be red and inflamed.

The cause is probably a combination of a genetic predisposition along with a possible fungal infection such as malassezia. This gives a clue as to how the condition is managed. As ever, emollients and soap substitutes are the starting point. The possible role of fungi mean that topical antifungals are often used, in combination with topical steroids, but care needs to be taken – especially where the face is affected – not to overuse steroids. An alternative that is increasingly used on the face is one of the calcineurin inhibitors such as pimecrolimus or tacrolimus. Although they can cause some initial irritation, if patients persist, this often settles, and there are far fewer side effects than with topical steroids. Oral antifungals are also a possible option in some cases.

Reference

1. Primary Care Dermatology Society. Clinical guidance: atopic eczema, updated April 2019. http://www.pcds.org.uk/clinical-guidance/atopic-eczema