What are the treatment options for non-plaque psoriasis subtypes, including guttate, inverse, pustular, and erythrodermic psoriasis?

Treatment Options for Non-Plaque Psoriasis Subtypes

For non-plaque psoriasis subtypes including guttate, inverse, pustular, and erythrodermic psoriasis, treatment should be tailored to the specific subtype, with biologics like ustekinumab recommended for moderate-to-severe cases of pustular and erythrodermic psoriasis, while topical therapies and phototherapy are preferred for guttate and inverse psoriasis. 1

Guttate Psoriasis

• Guttate psoriasis is characterized by dew-drop-like, 1-10mm salmon-pink papules with fine scale, typically found on the trunk and proximal extremities 1
• In most cases, guttate psoriasis is self-limiting and may resolve without treatment within 3-4 months, though up to 39% may progress to chronic plaque psoriasis 2
• First-line treatment options include:
  • Low concentrations of topical coal tar and dithranol due to the lower tolerance of erupting guttate psoriasis to topical treatments 1
  • Topical corticosteroids and calcipotriol cream as first-line therapy 2
  • Ultraviolet B (UVB) phototherapy, which is especially helpful and has the most robust evidence for efficacy 1, 2
• If streptococcal infection is present (common trigger):
  • Investigate for evidence of streptococcal infection 1
  • Treat persistent streptococcal infection with phenoxymethyl penicillin or erythromycin 1
  • Consider referral to otolaryngologist for tonsillectomy if repeated attacks occur after documented episodes of tonsillitis 1
• Second-line therapy for resistant cases:
  • Methotrexate or cyclosporine 2
  • Biologics for severe and refractory cases 2

Inverse (Flexural) Psoriasis

• Inverse psoriasis affects skin folds with erythematous plaques that have minimal scale due to the moist nature of these areas 1
• Common locations include axillary, genital, perineal, intergluteal, and inframammary areas 1
• Treatment considerations:
  • Great care should be taken when using dithranol on sensitive areas such as flexures and genitalia 1
  • Low to moderate potency topical corticosteroids are preferred to avoid skin atrophy 3, 4
  • Vitamin D analogues such as calcipotriene combined with hydrocortisone can be used for 8 weeks 3
  • Ustekinumab can be used as monotherapy for moderate-to-severe cases, though evidence is limited 1

Pustular Psoriasis

Localized Pustular Psoriasis (Palms and Soles)

• Characterized by multiple sterile pustules on palms and soles 1
• Treatment options include:
  • Moderately potent topical corticosteroids (British National Formulary grade III) to relieve symptoms 1
  • Topical coal tar and dithranol may provide some benefit 1
  • Systemic retinoids (acitretin) have shown some success 1
  • Ustekinumab at 90mg dose has shown 67% clearance rate compared to 9% with 45mg dose in patients with palmoplantar pustular psoriasis 1

Generalized Pustular Psoriasis

• An uncommon, severe form accompanied by fever and toxicity with widespread pustules on an erythematous background 1
• Treatment approach:
  • Initial management usually consists of hospital admission and systemic agents 1
  • Biologic therapy, particularly infliximab (used in over half of reported cases), has shown effectiveness 5
  • Other effective biologics include etanercept, ustekinumab, adalimumab, and anakinra 5
  • Ustekinumab is recommended as monotherapy for moderate-to-severe pustular psoriasis (strength of recommendation C) 1
  • Serious adverse events with biologics occur in approximately 10-12% of patients 5

Erythrodermic Psoriasis

• Characterized by generalized erythema covering nearly the entire body surface area with varying degrees of scaling 1
• Can develop gradually from chronic plaque disease or acutely with little preceding psoriasis 1
• Associated with altered thermoregulation leading to chills and hypothermia, fluid loss causing dehydration, and often fever and malaise 1
• Treatment approach:
  • Hospital admission is typically required with initial management using systemic agents 1
  • Infliximab was used in over half of reported cases with good efficacy 5
  • Ustekinumab is recommended as monotherapy for moderate-to-severe erythrodermic psoriasis (strength of recommendation C) 1
  • Other biologics that have been successfully used include etanercept, adalimumab, and anakinra 5
  • Cyclosporine, infliximab, and acitretin are suggested treatments by the American Academy of Dermatology 4

General Treatment Considerations for All Non-Plaque Subtypes

• Assessment for treatment selection should include:
  • Patient symptoms (pain, bleeding, itching)
  • Impact on quality of life
  • Response to previous localized therapy
  • Body surface area affected
  • Presence of incapacity or disability 1, 3
• Systemic treatment options for moderate-to-severe cases include:
  • Traditional systemics: methotrexate, cyclosporine, and acitretin 4, 6
  • Biologics: TNF inhibitors (infliximab, etanercept, adalimumab), IL-17 inhibitors, and IL-23 inhibitors 4, 6
  • Small molecule inhibitors: dimethyl fumarate and apremilast 6
• Phototherapy options:
  • Narrowband UVB is generally preferred for most subtypes 6
  • PUVA (psoralen plus UVA) may be considered for resistant cases 6
  • Phototherapy should be supervised by adequately trained personnel with regular equipment calibration 1

Important Caveats and Pitfalls

• Avoid systemic corticosteroids in psoriasis as they can cause disease flare during taper 4
• Commercial sunbeds (emitting UVA) are rarely effective in psoriasis and may cause significant side effects; their use is not recommended 1
• Combination of systemic agents should be approached with caution due to potential additive toxicity 4
• When using cyclosporine for psoriasis, start with 2.5 mg/kg/day divided twice daily, with potential increases up to 4 mg/kg/day based on response 7
• Be aware that transformation of psoriasis to more severe forms has been reported with cyclosporine treatment (9 cases of pustular and 4 cases of erythrodermic psoriasis) 7