Skin Pathology, Case 4

• A 25-year-old male presents to his dermatologist with well-demarcated, scaly, pink to salmon-colored plaques over the elbows. Areas of “pin-point” bleeding are noted when the scales are lifted off the surface of the plaque.

Epidermal thickening (acanthosis)

Parakeratosis

Downward projections of epidermis = “rete ridges”

Parakeratosis

Dermal papillae

Dermal papilla with dilated bloodvessels(when scale is lifted from plaques minute bleeding is seen – Auspitz sign. This is because of the close proximity of the dilated blood vessels to the overlying parakeratotic scale)

Small clusterof neutrophils in parakeratotic stratumcorneum

                                                                      

Psoriasis of the legs

                                                                           

Psoriasis. A rather small amount of the characteristic silvery scale is presenton these psoriatic plaques.

                                                                      

Patient with severe psoriatic arthritis. There is marked deformity and destruction of the digits. The nail plates are thickened and hyperkeratotic. Some psoriatic skin lesions are present.