Residency · Residency · Family Medicine

Eczema and Psoriasis: Long-Term Management in Primary Care

Introduction

Atopic dermatitis (eczema) and psoriasis are chronic, relapsing inflammatory skin diseases that together affect over 10% of the population. Family physicians manage the majority of these patients and must be skilled in long-term treatment strategies, trigger avoidance, comorbidity screening, and appropriate referral to dermatology.

Atopic Dermatitis

Epidemiology and Pathophysiology

Atopic dermatitis affects 15 to 20% of children and 7 to 10% of adults. It is part of the atopic triad along with asthma and allergic rhinitis. The disease is driven by epidermal barrier dysfunction, often related to filaggrin gene mutations, and Th2-mediated immune dysregulation. This combination leads to increased transepidermal water loss and susceptibility to irritants and allergens.

Clinical Presentation by Age

In infants, atopic dermatitis presents as erythematous, weeping, crusted plaques on the face, scalp, and extensor surfaces. In children, the pattern shifts to lichenified plaques in flexural areas, particularly the antecubital and popliteal fossae. Adults may have widespread xerosis, hand eczema, lichenification, and facial involvement.

Diagnosis

The diagnosis is clinical, based on the Hanifin and Rajka criteria or the simplified UK Working Party criteria. Key features include pruritus, a chronic or relapsing course, typical morphology and distribution, and a personal or family history of atopy. Biopsy is rarely needed but may be considered when the diagnosis is uncertain.

Treatment Approach

Foundation: Skin Care

Emollients should be applied liberally at least twice daily and immediately after bathing using the "soak and seal" technique. Fragrance-free products are essential, and soap-based cleansers should be avoided. Lukewarm baths lasting 5 to 10 minutes, followed by patting dry and applying emollient within 3 minutes, form the core of skin care.

Topical Anti-Inflammatory Therapy

Topical corticosteroids (TCS) are the mainstay of flare management. Low-potency formulations such as hydrocortisone 1 to 2.5% are appropriate for the face and intertriginous areas. Mid-potency agents like triamcinolone 0.1% are used on the body. High-potency agents such as clobetasol 0.05% are reserved for lichenified areas in short courses. Topical calcineurin inhibitors (tacrolimus and pimecrolimus) serve as steroid-sparing options for the face, eyelids, and maintenance therapy. Crisaborole, a PDE4 inhibitor, is approved for mild-to-moderate disease in patients aged 3 months and older.

Systemic Therapy

Dupilumab, an anti-IL-4/IL-13 monoclonal antibody, is the first-line biologic for moderate-to-severe atopic dermatitis and is highly effective. JAK inhibitors such as abrocitinib and upadacitinib offer oral options for moderate-to-severe disease. Traditional immunosuppressants including methotrexate, cyclosporine, and azathioprine are used less frequently now. Referral to dermatology is appropriate for initiation and monitoring of systemic agents.

Psoriasis

Epidemiology and Pathophysiology

Psoriasis affects 2 to 3% of the population worldwide. It is a Th17/IL-23-driven immune-mediated disease with genetic predisposition, particularly linked to HLA-Cw6. The disease involves accelerated keratinocyte turnover, with the normal 28-day cycle reduced to 3 to 4 days. Psoriasis is associated with significant systemic comorbidities.

Clinical Variants

Plaque psoriasis accounts for 90% of cases and presents as well-demarcated, erythematous plaques with silvery-white scale on extensor surfaces, the scalp, and the lumbosacral area. Guttate psoriasis features small, droplet-shaped lesions and is often post-streptococcal in children and young adults. Inverse psoriasis presents as smooth, erythematous patches in intertriginous folds. Pustular psoriasis involves sterile pustules and can be localized (palmoplantar) or generalized, with the latter constituting a medical emergency. Erythrodermic psoriasis involves diffuse erythema covering more than 90% of body surface area and requires urgent management.

Psoriatic Arthritis

Psoriatic arthritis occurs in 30% of psoriasis patients and should be screened for using the PEST (Psoriasis Epidemiology Screening Tool) or CASPAR criteria. Patterns include asymmetric oligoarthritis, symmetric polyarthritis, DIP-predominant disease, spondylitis, and arthritis mutilans. Early referral to rheumatology is critical to prevent joint destruction.

Treatment by Severity

Mild (BSA <3%)

Topical corticosteroids at mid-to-high potency for the body and low potency for the face and folds are first-line. Vitamin D analogs such as calcipotriene, often combined with betamethasone, are effective. Coal tar preparations work well but are cosmetically challenging. Topical retinoids such as tazarotene are useful for thick plaques.

Moderate-to-Severe (BSA >3-10% or significant functional impairment)

Phototherapy with narrowband UVB (NB-UVB) is first-line, administered 2 to 3 sessions per week. Methotrexate at 7.5 to 25 mg weekly requires monitoring of CBC, liver function, and renal function. Apremilast, a PDE4 inhibitor, is an oral option that is well-tolerated with moderate efficacy. Biologic agents have transformed outcomes: anti-TNF agents (adalimumab, etanercept), anti-IL-17 agents (secukinumab, ixekizumab), and anti-IL-23 agents (guselkumab, risankizumab) allow many patients to achieve PASI 90 to 100, representing near-complete clearance.

Comorbidity Screening in Psoriasis

Cardiovascular disease screening is essential because psoriasis is an independent risk factor; lipids, blood pressure, and glucose should be monitored. Metabolic syndrome, with its increased prevalence of obesity, diabetes, and dyslipidemia, should be assessed. Depression and anxiety should be screened for regularly, as psoriasis significantly impacts quality of life. Non-alcoholic fatty liver disease is relevant particularly when considering methotrexate. Joint symptoms suggestive of psoriatic arthritis should be asked about at every visit.

Differentiating Eczema from Psoriasis

Key Clinical Pearls

Emollients are the cornerstone of eczema management and should never be omitted, regardless of disease severity. Steroid phobia is common among patients, and education on appropriate use, potency selection, and the safety of intermittent long-term use is important. All psoriasis patients should be screened for psoriatic arthritis at every visit because early detection prevents irreversible joint damage. Psoriasis is a systemic disease, and cardiovascular risk screening is as important as skin management. Both conditions have significant mental health impacts, and quality of life and depression should be routinely assessed.

References

1. Eichenfield, L. F., et al. (2014). Guidelines of care for the management of atopic dermatitis. Journal of the American Academy of Dermatology, 71(1), 116-132.
2. Menter, A., et al. (2019). Joint AAD-NPF guidelines of care for the management of psoriasis with systemic therapy. Journal of the American Academy of Dermatology, 80(4), 1029-1072.
3. Wollenberg, A., et al. (2020). European guideline on atopic eczema. Journal of the European Academy of Dermatology and Venereology, 34(12), 2717-2744.
4. Takeshita, J., et al. (2017). Psoriasis and comorbid diseases: Epidemiology. Journal of the American Academy of Dermatology, 76(3), 377-390.

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