Tackling the most common skin ailment

Eczema is the most common chronic inflammatory skin disease worldwide and derives from the Greek word meaning to ‘boil or bubble over’. It is responsible for 30 per cent of skin consultations in primary care. The prevalence of the condition in children is 15 per cent and affects between two and 10 per cent of adults.

Clinical features include skin dryness, redness, oozing, crusting and lichenification. Itch is the hallmark of this condition and causes much of the disease burden for those affected. It follows a relapsing/remitting course.

The terms ‘dermatitis’ and ‘eczema’ are often interchangeably used but eczema usually refers to atopic eczema. This condition affects people with an atopic tendency clustering more in those with hay fever, asthma and food allergies.

The cause of eczema is a combination of genetic, environmental and immunological factors which result in a defective skin barrier and dysregulation of the immune system.

There is emerging evidence that a significant chronic inflammatory burden such as that seen in eczema may increase the risk of cardiovascular disease (BMJ 2018).

Clinical assessment
Eczema can be classified into various subtypes. Atopic eczema is more common in children and varicose (stasis) eczema, nummular and pompholyx eczema is more common in adults.

Diagnosis
Diagnosis is clinical but NICE recommend that the following criteria are fulfilled:
The patient must have pruritus and three or more of the following:

• Dry skin for the previous year.
• Onset of signs/symptoms in the first two years of life.
• Atopy or a history of atopy.
• Personal history of flexural eczema (or extensor in children under 18/12 months).
• Visible flexural eczema.

Management of eczema
There have been recent updates to eczema management with publication of the NICE guidance on antimicrobials in eczema (March 2021), updates from the Primary Care Dermatology Society 2022 (PCDS), new NICE Guidelines on atopic eczema in under 12s (March 2021) and The American Academy of Dermatology Guidelines (2023).These updates have been incorporated in the practical management and prescribing tips below for primary care with useful patient resources also referenced.

The Covid pandemic has highlighted the significance of how lifestyle impacts on eczema, with increased instances of eczema in healthcare workers because of prolonged use of PPE. In addition there were increased incidences of hand eczema in school children due to the practice of hand hygiene during Covid.

The significance of some avoidance measures and simple lifestyle strategies cannot be overstated and time spent in communication of these initially to patients/families remains essential to success of treatment and reduction of flares/relapses going forward. Indeed teenagers presenting with the condition or chronically affected by it should receive occupational advice on future career choices (eg. hairdressing ,dentistry, nursing etc). These key lifestyle measures are summarised below.

1. Lifestyle modifications
The Eczema Written Action Plan (EWAP) produced by the University of Bristol 2017 is an excellent resource for primary care that is both child friendly but lists most of the ‘eczema essentials’ as above summarised.

A useful resource for emollients is available as a fact-sheet on the National Eczema Society website.

This summarises in great detail different types, and lists lots of examples of commonly available moisturisers with unique properties-a time-saving resource for primary care .

The Covid pandemic has highlighted the significance of how lifestyle impacts on eczema with increased instances of eczema in healthcare workers because of prolonged use of PPE. In addition, there was a significantly increased incidence of hand eczema in school children due to the practice of hand hygiene during Covid.

2. Topical steroids
These are available in creams or ointments and the lowest appropriate potency of topical steroid should be prescribed to inflamed skin for 7-14 days with tapering of the potency of steroid gradually thereafter. Examples of the commonly prescribed steroids are listed below with usual sites of application. A more comprehensive list of topical steroids is available on the National Eczema Society website. Some common examples and sites of use are listed below.

The quantity of steroid prescribed is based on the Fingertip unit and a summary of these estimates for adult and child are as below. Two FTU s of cream is equivalent to one gram of topical steroid. In general, ointment is better if the skin is dry with cream preferable if the skin is weepy.

Once eczema has been brought under control, the use of the steroid weekend regime may be considered for those who have had frequent exacerbations. For a period of three months the usual steroid cream used may be applied to the sites of recurrence on the two weekend days only each week. Longer term, the topical calcineurin inhibitors might be preferable used in this way.

The National Eczema Society and Irish Skin Foundation have excellent patient information leaflets, and online resources regarding fingertip units, and topical steroid application, school packs etc. for more detail on the above.

3. Bandaging/Wet wraps
Applying emollient and topical steroid under occlusion increases absorption of both. Bandages (e.g., tubifast, icthopaste) are particularly helpful when added, and double up as a physical barrier to scratching. These are more widely used in secondary care, especially when potent topical steroids are being used.

4. Topical Calcineurin Inhibitors
These topical anti-inflammatory agents lack the long-term side effects of steroids (skin atrophy, striae etc.) especially on the face. Therefore, they are particularly useful in treatment of mild to moderate eczema of the face, eyelids, neck and skin folds. Their use is advisable where topical steroid creams have failed, or where there is serious risk of adverse effects with further steroid cream use.

Tacrolimus (Protopic) and Pimecrolimus (Elidel) are the agents in use and their characteristics are summarised below:

5. Secondary Skin Infections

• Bacterial infections. If antibiotics are indicated, then topical fusidic acid three times daily for 5-7 days for localised infections is recommended. Swabs are not required first unless the infection is recurrent, or where the eczema is worsening and not responding to usual therapies. If infection is more widespread, then Flucloxacillin orally is first line. In penicillin-unsuitable cases then clarithromycin is preferable, or erythromycin if patient is pregnant. It is important to stop topical calcineurin inhibitors if infection is suspected. If recurrent infections are occurring, then nasal swabs for staphylococcus aureus should be taken and decolonisation (naseptin etc.) used.
• Viral infections. Blisters or cold sores around a child or adult with atopic eczema can lead to widespread infection known as eczema herpeticum. These patients are generally unwell and require secondary referral for antivirals /supportive therapies.
• Superimposed fungal infections can also occur more in those with eczema, e.g. tinea pedis.

6 Other Useful Primary Care Tools

• Antihistamines. Although these are not recommended for routine use for itch they can, in shorter courses, help. Sleep upset from itch may be reduced with evening use of sedating antihistamines (e.g. chlorpheniramine).
• Potassium permanganate soaks or bathing. Very useful in recurrently infected lower limb eczema which is weeping .Vaseline applied to toenails etc. stops discoloration.
• A few small, randomised control trials have suggested a possible beneficial role for
  Vitamin D supplementation during the winter months. Larger controlled trials are ongoing.

7 Newer Potential Topical therapies

• Crisaborole ointment Phosphodiesterase 4 Inhibitor, FDA approved for mild to moderate eczema in adults and children over two years but efficacy uncertain.
• Ruxolitinib ointment Janus Kinase (JAK) inhibitor approved in 2021 FDA for short term treatment of mild to moderate or resistant eczema in immunocompetent patients over 12 years, very promising but more research on long-term safety awaited.

These are currently subject of ongoing research and though available in USA are not yet available here.

Referral to Secondary Care
This should be considered in the following situations:

1. Severe Eczema-not responding to primary care treatments or very extensive.
2. Where there is significant psychological or social upset with eczema.
3. Where a child has also failure to thrive, or significant sleep upset despite treatments.
4. Frequent flares (a few times monthly despite treatment).
5. Concerns over amount of topical steroids being used.
6. Eczema Herpeticum.
7. Diagnostic uncertainty.

Secondary Care Managements
1. Physical Therapies

• Ultraviolet light UVB and PUVA are secondary level treatments available for recalcitrant eczema.

2. Systemic Therapies

• Immunosuppressive agents. These agents are the realm of secondary care and used in the long-term control of severe disease. These agents include methotrexate, azothiaprine, mycophenolate mofetil and cyclosporine. They take weeks to work with careful monitoring required.
• Biological agents such as Dupilumab block specific steps in the inflammatory pathway. It is an interleukin 4/IL3 receptor blocker approved by FDA for treatment of adults and children six months and over with moderate to severe eczema not fully controlled with topical therapies alone. They are ideal for those who are not candidates for the above immunosuppressives or have had a failed response to them. Cost is the major factor with these medications and the delivery is via subcutaneous injections two weeks apart. Side effects include ocular conjunctivitis, facial redness, and joint pains.
• JAK inhibitors such as Abrocitinib is approved for use in moderate to severe eczema where disease has not been controlled with immunosuppressives or biologics or when both agent groups are contraindicated.

Conclusions
Eczema is an extremely common condition in Irish children and adults. It causes a significant symptom burden and can adversely affect quality of life. Lifestyle modifications play a pivotal role in treatment, prevention and medication usage reduction. Familiarity with the indications and potential pitfalls of the various treatments are essential.