What's wrong with Mia?

Diagnosis

Although the clinical subtypes of psoriasis in children are similar to adults, diagnosis in children is more challenging.

In a study of 887 patients <18 years, the most common subtypes of psoriasis were⁶:

• plaque psoriasis (73.7%)
• guttate psoriasis (13.7%)
• scalp psoriasis (7.6%)

• pustular psoriasis (1.1%)

Lesions in children may be thinner, softer, less scaly, less well defined than in adults⁷ and the clinical symptoms at presentation also vary according to the age group⁸. In addition, skin biopsy is performed less often in younger patients compounding the difficulty⁹.

Professor Vakirlis describes the dermatoscopic findings that define childhood psoriasis.

Childhood psoriasis is also sometimes misdiagnosed because it is confused with other skin diseases such as atopic or nummular dermatitis, otitis externa, pityriasis rosea, or superficial fungal infections⁵. Figure 2 details the clinical features of psoriasis to look out for in children of different ages.

Figure 2. Clinical features of paediatric psoriasis by age (adapted from Pinson et al.⁹).

Find out from Professor Vakirlis more on the challenges of diagnosing childhood psoriasis and the dangers of under- or misdiagnosis.

Triggers

It is worth noting that there are a number of factors that can trigger or exacerbate psoriasis in children. These include environmental and emotional stress, skin trauma (Koebner phenomenon) increased body mass index (BMI), second-hand cigarette smoke, Streptococcus and other infections, Kawasaki disease, withdrawal of systemic corticosteroids, and, tumour necrosis factor (TNF)α inhibitor medications¹⁰.

While robust evidence is lacking, Professor Vakirlis describes some of the common environmental factors that can initiate or exacerbate childhood psoriasis.

Disease severity

Defining severity is also more difficult in children. Common measures used in research such as PASI (psoriasis area and severity index) and PGA (physician’s global assessment) haven’t been fully validated in children and severity is not solely related to body surface area (BSA). It also depends on body areas affected and individual perception^5,11. For example, scalp psoriasis around the frontal hairline can cause significant impairment in quality of life (QoL) due to its visibility¹².

Professor Paller describes how she measures severity in her clinic.

Quality of life

Psoriasis has a large impact on QoL and studies have shown psoriasis to cause one of the greatest QoL impairments among skin diseases¹³, comparable with other serious paediatric chronic diseases such as arthritis, asthma and diabetes¹⁴.

Professor Vakirlis discusses the symptoms that reach beyond the stigma associated beyond physical symptoms.

Patient

The social development domain of the Children’s Dermatology Life Quality Index (CDLQI) shows that children with psoriasis are particularly impaired¹³ with affected emotional and school functioning¹⁵. Unfortunately children often experience teasing, social exclusion by peers, name calling, intimidation, and even in some cases physical violence⁵. In addition, psoriasis limits recreational activity in at least 15–30% of children with psoriasis¹⁶ and the pruritus, sweating, and visible lesions have the greatest detrimental effect on QoL¹⁷.

Two aspects rarely considered are the degree of skin scales that children shed and the odour of affected skin. Both are significant problems for many children which add to their embarrassment about their bodies. Dissatisfaction with body image is important to ascertain from patients and asking children to rate their satisfaction with the appearance of their skin on a scale from 1 to 10 is a good way to assess this issue objectively and to validate this concern as being medically important and not just a question of vanity¹⁸.

CDLQI

The CDLQI questionnaire has ten questions based on the experiences of children with skin disease over the past week, and has been validated for children aged four to 16 years¹⁵. There is also a cartoon version available for the younger children in this age range¹⁹ which is popular with both parents and patients. This is available at this external link.

Family

Psoriasis also has a considerable impact on the families of children suffering with the symptoms of the condition. In many cases, parents of affected children may experience the additional emotional burden of having passed psoriasis on to their child²⁰.

Professor Amy Paller describes the tremendous burden of childhood psoriasis on the whole family.

In paediatric patients caregivers have to be involved in disease-related activities, such as doctor visits, and application of treatment(s)²¹. A study designed to understand parents’ perspectives on young people’s daily life with psoriasis revealed that parents perceived caring for their child as an ongoing stressful learning process having to balance toning down the impact of psoriasis while acknowledging their young people’s needs of multiple treatments and support²⁰.

Another study measured the burden of psoriasis on caregivers and results indicated that psoriasis can be distressing for parents and children alike, disrupting everything from family outings to household activities. Out of 31 parents who participated in the survey, nearly half said they felt sad or frustrated because of their child’s disease. Almost two-thirds of parents reported that they had to change their or their family’s activities to accommodate the needs of their child’s psoriasis²².

Since parental response to any chronic illness can affect the child’s adaptation, interventions such as counselling, stress management and problem solving strategies, will promote better mental health in parents and facilitate better family functioning and care for their children²³.

Treating children is very different from adults. We asked Professor Vakirlis about the special challenge of childhood psoriasis and how it can differ between younger children and adolescents.

Psoriatic arthritis

While the prevalence of psoriatic arthritis is lower than that in adults affected by psoriasis, there is still an estimated prevalence of 0.7% for all children with psoriasis, rising to 1.2% of patients with psoriasis by 18 years. Indeed, psoriatic arthritis is estimated to account for 6–8% of all inflammatory arthritis cases in children²⁷.

Obesity and metabolic syndrome

While information about the incidence of comorbidities among children with psoriasis is more limited than that in adults, studies have shown increased risk of obesity and cardiovascular risk factors among children with psoriasis compared with those without^28,29 (Figure 3).

Figure 3. Increased risk of comorbidities in childhood psoriasis from a German (Augustin et al.²⁸) and US study² (Paller et al.⁵).
NS; not significant.

Psychiatric disorders

Studies have also shown that children with psoriasis are also at increased risk for psychiatric disorders and receiving drugs for psychiatric disorders compared with those without^29–31.

Figure 4. Increased risk of psychiatric comorbidities in paediatric psoriasis from a Danish (Todberg et al.³¹) and two US studies (Kimball et al.³⁰; Paller et al.²⁹). % figures are from adjusted hazard ratios and fold changes from incidence rate ratios. ND; not determined; NS, not significant.

Regular screening

Given the recognised link between psoriasis and joint and cardiovascular factors and psychological disorders, guidelines recommend regular screening for children with psoriasis^10,26.

• Psoriatic arthritis – routine screening
• Weight – routine assessment for obesity status
• Hypertension – annual screening
• Diabetes –screening every three years
• Depression – routine screening
• Substance abuse – yearly from 11 years

Association of disease severity with comorbidities is unclear. Obesity may be associated with psoriasis severity as it has been shown in one study that a greater number of patients with mild psoriasis were overweight and a greater number of patients with moderate-to-severe psoriasis were obese³². However, a more recent study showed no difference in disease severity with any comorbidity²⁹ and so it is important to be on the lookout for comorbidities even in patients with milder disease.

Topical treatments

Topical treatments are considered first-line therapy in children with mild psoriasis. However, most topical medications are not approved for paediatric use, especially in children under 12 years, and so are extensively used off-label³⁴. Topical treatments included in paediatric guidelines include corticosteroids, calcineurin inhibitors, vitamin D analogues (and various combinations), tazarotene, anthralin and coal tar¹⁰.

Professor Paller describes a typical topical treatment regime and why topical treatments are not popular with adolescent patients.

Phototherapy

Phototherapy can be considered as the first-line treatment in patients with more extensive psoriasis and is generally safe and effective in children³⁵. Excimer laser and UVA light with various forms of psoralen (topical, and in some cases oral psoralen plus UVA [PUVA] photochemotherapy) may be used in children with psoriasis and may be efficacious and well tolerated. However, PUVA therapy is contraindicated in children under 12 years because of its related toxicity and probable side effects (nausea, vomiting, photosensitisation and ocular and hepatic toxicity)³⁶.

Phototherapy options have limited supporting evidence and the potential for early skin aging (age spots, wrinkles, loose skin) and increased risk of developing skin cancer needs to be considered³⁶.

Systemic treatments

Systemic treatments of childhood psoriasis can be considered in the case of more severe disease, lack of response to more conservative therapies and impaired physical functioning or QoL¹⁰. However, the majority of systemic treatments are not specifically approved for the treatment of psoriasis in children³⁶.

• Methotrexate is effective in the treatment of moderate-to-severe plaque psoriasis, and it is the most prescribed drug for paediatric psoriasis but should be avoided in children for long-term therapy because of cumulative toxicity³⁷  
• Ciclosporin A is not approved for childhood psoriasis but it is approved for the prevention of transplant rejection in children above 6 years³⁵
• The retinoid acitretin is effective in paediatric plaque psoriasis, particularly in cases of pustular and erythrodermic disease, but it can take three months of treatment and retinoids are best avoided in young females of childbearing potential because of their teratogenicity³⁶
• Fumaric acid esters (FAE) are used extensively in Germany for psoriasis in adults. There are not many studies on the efficacy of these drugs in children but they may be suitable in cases where methotrexate is contraindicated³⁶
• Apremilast is a phosphodiesterase Type 4 inhibitor approved for use in adults with psoriasis or psoriatic arthritis³⁸. It has been tested in children and phase II results are described in the clinical trials section of the Learning Zone.

Biologic treatments

While there are numerous biologic treatment options for adults with moderate-to-severe psoriasis, the case for approved therapies for paediatric patients is unfortunately different.

Two anti-TNF therapies are approved for use in paediatric patients with moderate-to-severe psoriasis, etanercept³⁹ and adalimumab⁴⁰. However, there are two other anti-TNF therapies for adults with psoriasis that are not approved for paediatric use in psoriasis. Infliximab is approved for use in children with Crohn’s disease and ulcerative colitis, but not psoriasis⁴¹. Certolizumab pegol effectively treats paediatric patients with juvenile idiopathic arthritis with a safety profile similar to other TNF inhibitors but is not approved for paediatric use or being investigated in paediatric trials for psoriasis³³.

The IL-12/23 inhibitor ustekinumab is approved for use in paediatric patients with moderate-to-severe psoriasis⁴² and the IL-17 inhibitor ixekizumab was approved in the US and Europe in 2020^43,44. More recently, a second IL-17 inhibitor, secukinumab, also received EU approval for the treatment of moderate-to-severe plaque psoriasis in children over six years of age⁴⁵.

Professor Matthias Augustin, Director of the Institute for Health Services Research in Dermatology and Nursing, in Hamburg, Germany, comments on the benefits and challenges in using IL-17 targeting biologics for paediatric psoriasis.

While a number of clinical trials are ongoing, there is currently a lack of data on the long-term efficacy and safety of biologics in paediatric psoriasis³³.

What biologic treatments are currently being investigated for paediatric psoriasis? Professor Matthias Augustin summarises the state of investigational research on biologics for paediatric psoriasis.

What do parents think about biologic treatment for their child? Professor Paller describes the reservations that parents might have and the information that it is important for them to consider in treatment discussions.