Cutaneous sarcoidosis masquerading as psoriatic plaques

Area of Science:

• Dermatology
• Immunology
• Pathology

Background:

• Sarcoidosis is a multisystem inflammatory disease characterized by non-caseating granulomas.
• Its etiology is multifactorial, involving genetic predisposition, environmental factors, and immune system dysregulation.
• Cutaneous sarcoidosis manifests in various forms, categorized as specific (granulomatous) or non-specific (inflammatory) lesions.

Observation:

• Psoriasiform lesions represent an uncommon presentation of cutaneous sarcoidosis, reported in as few as 0.9% of cases.
• These lesions typically appear as infiltrated, round or oval, brownish-red plaques on the face, extremities, and trunk.
• While clinically resembling psoriasis, histological examination reveals non-caseating granulomas in the dermis.

Findings:

• Psoriasiform sarcoidosis is a rare variant of cutaneous sarcoidosis.
• Histopathology is crucial for differentiating psoriasiform sarcoidosis from psoriasis, showing non-caseating granulomas.
• Systemic involvement, particularly pulmonary, may coexist with psoriasiform lesions.

Implications:

• Recognizing psoriasiform sarcoidosis is important for accurate diagnosis and appropriate management.
• This rare presentation highlights the diverse clinical spectrum of sarcoidosis.
• Further research may elucidate the specific pathomechanisms underlying this uncommon manifestation.