Image Based Question-70179

Identify this Skin Pathology:

A. Lichen Planus

B. Psoriasis

C. Pemphigus

D. Pemphigoid

Correct Answer » B Explanation

Ans:B. Psoriasis.

PSORIASIS.

• Psoriasis is a chronic inflammatory dermatosis.

• The lesions are characterised by brownish-red papules and plaques which are sharply demarcated and are covered with fine, silvery white scales.

• As the scales are removed by gentle scrapping, fine bleeding points appear termed Auspitz sign.

• Commonly involved sites are the scalp, upper back, sacral region and extensor surfaces of the extremities, especially the knees and elbows. In about 25% of cases, peculiar pitting of nails is seen.

• Histologically, the following features are observed in fully-developed lesions :

1. Acanthosis with regular downgrowth of rete ridges to almost the same dermal level with thickening of their lower portion.
2. Elongation and oedema of the dermal papillae with broadening of their tips.
3. Suprapapillary thinning of stratum malpighii.
4. Absence of granular cell layer.
5. Prominent parakeratosis.
6. Presence of Munro microabscesses in the parakeratotic horny layer is diagnostic of psoriasis.