Introduction to Dermatology

Prof. S.Anandan, MD, DD*

• Caveats

No two skin diseases look alike

Most skin diseases have characteristic primary and secondary lesions

Primary skin lesions may be obliterated by secondary lesions

Complete examination of entire body is a necessity when confronted with a diffuse skin eruption.

• Points in history taking

Elicit nature and course of disease

Family history

Any other factors in disease exacerbation

Record the recent use of drugs

• Points in examining the skin:

Examining the entire skin surface

Use hand lens and adequate illumination

Look at nails, mucous membranes and hairs

Observe for distribution, individual lesions

• PRIMARY LESIONS

• Lesion Description Example

• Macule Circumscribed alteration of skin vitiligo colour <0.5cm size freckles

• Patch More than 0.5 c.m.

• Papule Circumscribed, solid elevated Lichen planus lesion of <0.5cm molluscum contagiosum

• Nodule Larger than 0.5 cm with depth neuro fibroma/dematofibroma

• Pustule Pus filled blister furuncle

• Plaque Circumscribed elevated plateau psoriasis, lupus vulgaris like elevation of skin of more than 0.5 cm

• Vesicle Fluid filled lesions of 0.5 cm size

* - Professor and HOD - Dermatology

Sri Ramachandra Medical College& Research Institute (Deemed University)