VHOSPITAL.CLINIC · Differential Diagnosis
Lichen Planus vs Psoriasis
Clinical comparison — shared symptoms, key differences, distinguishing diagnostic tests, treatment pathways, and when to seek urgent evaluation.
Condition Overview
Condition A
Lichen Planus
Lichen planus is an inflammatory condition affecting skin, mucous membranes, and nails, causing intensely itchy, flat-topped, purple papules. Oral lichen planus can cause erosive lesions; topical and systemic corticosteroids are used for treatment.
Condition B
Psoriasis
Psoriasis is a chronic autoimmune skin condition that causes rapid skin cell turnover, resulting in thick, red, scaly patches (plaques). It can affect any part of the body and is associated with psoriatic arthritis. Stress, infections, and certain medications can trigger flares.
Shared Symptoms — Why They're Confused
Both conditions present with 2 overlapping symptoms, making clinical differentiation essential.
Key Clinical Differences
Lichen Planus
- Intensely pruritic, flat-topped, purple polygonal papules
- Wickham's striae (white lacy lines on surface)
- Oral mucosa involvement (reticular pattern)
- Wrists, ankles, lower back, genital areas
Psoriasis
- Silvery-scaled plaques on extensor surfaces
- Auspitz sign: pin-point bleeding on scale removal
- Nail pitting, onycholysis
- Koebner phenomenon on trauma
Distinguishing Diagnostic Tests
| Test | Lichen Planus | Psoriasis |
|---|---|---|
| Lesion morphology | Flat-topped, violaceous (purple) papules with Wickham's striae | Raised erythematous plaques with silvery scales; Auspitz sign |
| Oral examination | Reticular white pattern or erosions inside cheeks — oral LP | No typical oral involvement (occasional exceptions) |
| Skin biopsy | Band-like lymphocytic infiltrate at dermo-epidermal junction — lichen planus | Epidermal acanthosis, parakeratosis, dilated capillaries — psoriasiform pattern |
Treatment Approaches
Lichen Planus
- •Potent topical corticosteroids
- •Hydroxychloroquine for systemic/generalised LP
- •Topical tacrolimus for oral LP
Psoriasis
- •Topical corticosteroids + calcipotriol
- •Biologics for moderate-severe psoriasis
- •Phototherapy (NB-UVB)
When Doctors Consider Each Diagnosis
🔵 Consider Lichen Planus when:
- →Purple flat-topped papules, Wickham's striae, oral white patches, wrists
🟢 Consider Psoriasis when:
- →Silvery extensor plaques, Auspitz sign, nail pitting, Koebner phenomenon
Explore Each Condition in Detail
Related Clinical Pages
Lichen Planus
Medical References
Content on this page is informed by evidence-based clinical sources including:
- World Health Organization (WHO)Global health guidance and disease classification
- National Health Service (NHS)UK clinical guidelines and patient information
- National Institute for Health and Care Excellence (NICE)Evidence-based clinical practice guidelines
- Centers for Disease Control and Prevention (CDC)US public health data and clinical recommendations
- PubMed – NCBIPeer-reviewed biomedical literature and clinical studies
- Cochrane LibrarySystematic reviews and meta-analyses in evidence-based medicine
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