Overview
Definition:
Psoriasis in children is a chronic, inflammatory, immune-mediated skin disease characterized by well-demarcated erythematous plaques with silvery scales
While less common than in adults, it can significantly impact a child's quality of life
It is often associated with an increased risk of comorbidities
The pathophysiology involves genetic predisposition, immune dysregulation (particularly T-helper 1 and 17 cells), and environmental triggers.
Epidemiology:
Childhood psoriasis accounts for approximately 0.7% to 3.7% of all psoriasis cases
Onset typically occurs before the age of 16
There is a bimodal age distribution for onset: one peak between 8-10 years and another in adolescence (13-15 years)
Boys and girls are equally affected
Family history is present in a significant proportion of affected children, often with adult-onset psoriasis in first-degree relatives
There is a higher association with psoriatic arthritis in children compared to adults.
Clinical Significance:
Pediatric psoriasis poses unique challenges due to the developing immune system, potential for long-term sequelae, and significant psychosocial impact on children
Accurate diagnosis and appropriate management are crucial to prevent disease progression, manage comorbidities, and improve the child's well-being and participation in daily activities
Understanding the nuances of topical and systemic therapies is vital for DNB and NEET SS preparation.
Clinical Presentation
Symptoms:
Itching (pruritus) is a common complaint, ranging from mild to severe
Discomfort and pain may occur, especially with fissuring
Lesions are often asymptomatic
Impact on sleep, school attendance, and social interactions is frequently reported.
Signs:
Typical lesions are erythematous, well-demarcated plaques with characteristic silvery-white scales
Common sites include the scalp, face, trunk, extensor surfaces of limbs, and diaper area (in infants, sometimes mimicking candidiasis)
Nail changes (pitting, onycholysis, discoloration) are seen in up to 50% of children
Psoriatic arthritis may present with joint swelling, stiffness, and pain, particularly in the knees, ankles, and digits.
Diagnostic Criteria:
Diagnosis is primarily clinical, based on characteristic morphology and distribution of lesions
A biopsy may be performed if the diagnosis is uncertain, showing epidermal hyperplasia, parakeratosis, and dermal inflammatory infiltrates
There are no specific laboratory diagnostic criteria for psoriasis itself, but investigations may be used to rule out other conditions or assess for comorbidities.
Diagnostic Approach
History Taking:
Detailed history regarding onset and duration of lesions, progression, previous treatments and responses, presence of itching or pain, family history of psoriasis or other autoimmune diseases
Inquire about triggers such as infections (e.g., streptococcal pharyngitis preceding guttate psoriasis), trauma (Koebner phenomenon), stress, and medications
Assess impact on quality of life, including school, social, and psychological aspects
Screen for comorbidities like obesity, metabolic syndrome, inflammatory bowel disease, and atopy.
Physical Examination:
Thorough dermatological examination to assess morphology, distribution, and extent of lesions
Look for typical plaques, scalp involvement, nail changes (pitting, onycholysis, Beau's lines, crumbling), and mucosal lesions
Examine joints for swelling, tenderness, and reduced range of motion, especially in children with suspected psoriatic arthritis
Assess for evidence of Koebnerization
Perform a complete physical examination to identify associated signs of comorbidities.
Investigations:
No specific blood tests are diagnostic for psoriasis
Complete blood count (CBC), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) may be elevated in active disease or associated arthritis
Liver function tests (LFTs) and renal function tests (RFTs) are baseline investigations before starting systemic therapy
Vitamin D levels should be checked due to potential impact on bone health with systemic therapies
Rheumatoid factor (RF) and anti-CCP antibodies are usually negative in psoriatic arthritis
HLA-B27 testing can be considered in cases of suspected spondyloarthritis
Skin biopsy for histopathology can confirm diagnosis if clinically uncertain.
Differential Diagnosis:
Eczema (atopic dermatitis, seborrheic dermatitis), tinea corporis, pityriasis rosea, lichen planus, drug eruptions, secondary syphilis, pityriasis lichenoides et varioliformis acuta (PLEVA)
In infants, diaper psoriasis needs to be differentiated from candidiasis, irritant contact dermatitis, and atopic dermatitis.
Management
Topical Therapy:
First-line treatment for mild to moderate childhood psoriasis
Options include: Corticosteroids (low to mid potency, short-term use to avoid atrophy, e.g., hydrocortisone 1%, betamethasone 0.05% cream/ointment)
Calcineurin inhibitors (tacrolimus 0.03% ointment, pimecrolimus 1% cream) for sensitive areas like face and intertriginous regions
Vitamin D analogs (calcipotriol) and combination calcipotriol/betamethasone dipropionate formulations (use cautiously in children, often reserved for >6 years)
Coal tar preparations and dithranol (anthralin) are less commonly used due to staining and irritation
Emollients are essential for hydration and barrier function.
Phototherapy:
Used for moderate to severe psoriasis not responding to topical therapy
Narrowband UVB (NB-UVB) is the preferred modality
Treatment is given several times a week, with careful monitoring for phototoxicity and photocarcinogenesis
Excimer laser can be used for localized lesions.
Systemic Therapy:
Indicated for severe, recalcitrant psoriasis, psoriatic arthritis, or when topical/phototherapy is contraindicated or ineffective
Options include: Methotrexate (weekly dosing, requires folic acid supplementation, liver function monitoring)
Cyclosporine (short-term use for severe flares, requires renal function and blood pressure monitoring)
Acitretin (oral retinoid, teratogenic, requires strict contraception, liver function monitoring)
Biologics (e.g., etanercept, adalimumab, ustekinumab) are increasingly used for moderate to severe psoriasis and psoriatic arthritis in children
they target specific inflammatory pathways (TNF-alpha, IL-12/23, IL-17)
Careful screening for infections (especially tuberculosis) and regular monitoring are mandatory.
Supportive Care:
Education for the child and family about the chronic nature of the disease, treatment adherence, and trigger avoidance
Psychological support is crucial to address the emotional and social impact
Management of comorbidities such as obesity, metabolic syndrome, and inflammatory bowel disease
Regular follow-up to monitor disease activity, treatment response, and potential side effects
Nutritional assessment and counseling, especially if the child has associated conditions or is on systemic therapy.
Complications
Early Complications:
Skin infections (bacterial or fungal) due to compromised skin barrier
Exacerbation of psoriasis due to Koebner phenomenon (trauma, sunburn, infection).
Late Complications:
Psoriatic arthritis, which can lead to joint damage and disability if untreated
Increased risk of cardiovascular disease, metabolic syndrome, inflammatory bowel disease (Crohn's disease), and certain malignancies with long-standing, severe psoriasis and/or systemic immunosuppressive therapy
Psychosocial issues including depression, anxiety, social isolation, and reduced academic performance.
Prevention Strategies:
Gentle skin care to maintain skin barrier
Prompt treatment of infections
Stress management and avoidance of known triggers
Regular screening for comorbidities
Judicious use of topical and systemic therapies to minimize side effects
Multidisciplinary approach involving dermatology, rheumatology, pediatrics, psychology, and nutrition.
Prognosis
Factors Affecting Prognosis:
Age of onset (earlier onset may be associated with more severe disease and higher risk of comorbidities)
Extent and severity of skin and joint involvement
Response to initial treatment
Presence and management of comorbidities
Genetic predisposition.
Outcomes:
With appropriate management, significant improvement in skin lesions and quality of life can be achieved
However, psoriasis is a chronic condition, and relapses are common
Long-term remission is possible, but continuous monitoring and management are often required
Early and effective treatment of psoriatic arthritis can prevent long-term joint damage.
Follow Up:
Regular follow-up appointments are essential, with frequency determined by disease severity and treatment modality
Initially, monthly or bimonthly follow-ups may be needed for active treatment
As the disease stabilizes, follow-up intervals can be extended
Monitoring includes assessment of disease activity (e.g., Psoriasis Area and Severity Index - PASI), quality of life questionnaires (e.g., Children's Dermatology Life Quality Index - CDLQI), joint assessment, assessment for comorbidities, and monitoring for treatment-related adverse effects (laboratory tests, vital signs)
Family education and support should be an ongoing component of care.
Key Points
Exam Focus:
Childhood psoriasis is less common but has unique presentation and management challenges
Differentiate various types of psoriasis in children (plaque, guttate, inverse, pustular)
Topical steroids, vitamin D analogs, calcineurin inhibitors are first-line
Phototherapy for moderate disease
Methotrexate, cyclosporine, acitretin, and biologics for severe disease
Biologics target specific cytokines (TNF-alpha, IL-12/23, IL-17)
Psoriatic arthritis is a significant comorbidity
Screen for metabolic syndrome and IBD.
Clinical Pearls:
Use lower potency steroids for face and intertriginous areas
Calcineurin inhibitors are valuable alternatives to steroids in sensitive zones
Diaper area psoriasis needs differentiation from candidiasis
Strep pharyngitis is a common trigger for guttate psoriasis
consider throat swab
Nail changes are a strong indicator of potential psoriatic arthritis
Biologics require rigorous screening for TB and other infections.
Common Mistakes:
Over-reliance on potent topical steroids for prolonged periods leading to skin atrophy and telangiectasias
Inadequate treatment of psoriatic arthritis leading to irreversible joint damage
Failing to screen for comorbidities like IBD and metabolic syndrome
Misdiagnosing infantile or diaper psoriasis as fungal infection without considering other differentials
Inappropriate use of systemic agents without adequate monitoring or screening.