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.