Question

A 26-year-old male presented with erythematous plaques covered with silvery scales over the extensor surfaces of both arms. Punctate pitting was noted on examining the nails. What is the most likely diagnosis?

• A. Psoriasis
• B. Lichen Planus
• C. Eczema
• D. Pityriasis rosea

Hint:

In psoriasis, the combination of silvery scales on erythematous plaques and punctate nail pitting is key to making the diagnosis. It commonly affects extensor surfaces.

Answer 1

The Correct Option is A

The clinical presentation of erythematous plaques covered with silvery scales, particularly on the extensor surfaces of the arms, is characteristic of psoriasis. Psoriasis is a chronic inflammatory skin disorder that commonly affects the scalp, elbows, knees, and lower back. Key features of psoriasis include:
Silvery scales: The plaques are covered with a thick, silvery scale that can be easily removed to reveal a red, inflamed base.
Extensor surfaces: Psoriasis tends to affect the extensor surfaces of the limbs (e.g., elbows and knees), which is a distinguishing feature of the disease.
Punctate pitting: This is a hallmark sign of psoriasis, especially when examining the nails. Punctate pitting involves small depressions on the surface of the nails, which is a common finding in patients with psoriatic arthritis or psoriasis. Other conditions to consider:
Lichen Planus: A pruritic, inflammatory skin condition that presents with purple, polygonal, flat-topped papules, and does not typically cause silvery scales or punctate nail pitting.
Eczema: A skin condition characterized by itchy, inflamed skin, often in flexural areas (e.g., elbows and knees), and does not usually present with silvery scales or punctate nail pitting.
Pityriasis rosea: A self-limited skin condition that usually begins with a single herald patch, followed by a more generalized rash with a "Christmas tree" distribution, which does not fit the description provided in this case. Thus, the most likely diagnosis is Psoriasis.