APPROACH TO A PATIENT WITH

SKIN DISORDERSDr Subhasish Deb

Dept. General MedicineBurdwan Medical College

Skin is the largest organ in the bodyAdvantage: no special instrumentation requiredDisadvantage: minor differences in shape and

colour Imp to differentiate PRIMARY from

SECONDARY lesions Ex: if an examiner focuses on a linear erosion

overlying an area of erythema and scaling, he may incorrectly assume that the erosion is the primary lesion while redness and the scales are secondary. The correct interpretation would be that the pt has a pruritic eczematous dermatitis with erosions caused by scratching

Primary Skin Lesions1. MACULE

Flat – not raised above suface of surrounding skin

< 2 cm Coloured A Freckle or ephelid is a prototype

pigmented macule

2. PATCH Flat lesion Large, > 2cm Colour different from surrounding skin

3. PAPULE Small solid lesion, < 0.5cm diameter Raised above surface (palpable)

4. NODULE Larger in size, 0.5-5cm raised

Paplue: acne

Nodule: Dermal melanocytic nevus

5. TUMOUR > 5cm Solid, raised growth

6. PLAQUE Large, > 1cm Flat topped Raised lesion Edges may be distinct (psoriasis) or blend with

surrounding skin (eczematous dermatitis)

PLAQUE

Psoriasis

A

B

Exzematous dermatitis1 2

3

7. VESICLE Small, < 0.5cm diameter Fluid filled Raised above plane of skin

8. PUSTULE Vesicle filled with leukocytes

9. BULLA Fluid filled Raised Often translucent, > 0.5cm diam

Vesicle

Pustule

Bulla

10. WHEAL Erythematous Raised Papule or plaque Usually representing short lived vasodilatation and

vasopermeability

11. TELANGIECTASIA Dilated, superficial blood vessel

Wheal

Telangiectasia

Secondary skin lesions1. Lichenification : thickening of skin

characterized by accentuated skin fold markings

2. Scale : Excessive accumulation of stratum corneum

3. Crust : Dried exudate of body fluids that may be yellow (serous crust) or red (hemorrhagic crust)

Lichenification

Scales, ex: icthyosis Crust

4. Erosions : loss of epidermis without loss of dermis

5. Ulcer : loss of epidermis and at least a portion of the underlying dermis

6. Excoriation : linear, angular erosions that may be covered by crust and are caused by scratching

Erosion

Excoriation

Ulcer

7. Atrophy : An acquired loss of substance. In the skin, this may appear as a depression with intact epidermis (i.e loss of dermal or subcut tissue) or as sites of shiny, delicate, wrinkled lesion (i.e epidermal atrophy)

8. Scar : a change in skin secondary to trauma or inflammation. May be hypo or hyperpigmented

Atrophy Scar

Common Dermatological Terms1. Alopecia – Hair loss, may be partial or

complete2. Annular – Ring shaped lesion3. Cyst – soft, raised, encapsulated lesion filled

with semisolid or liquid contents4. Herpetiform – Grouped lesions5. Lechenoid – Violaceous to purpule, polygonal

lesions that resemble those seen in lichen plannus

6. Milia – Small, firm, white papules filled with keratin

7. Morbiliform – Generalized, small erythematous macules and/or papules resemble those seen in measles

8. Nummular – coin shaped9. Poikiloderma – skin that displays variegated

pigmentation, atrophy and telangiectases10. Polycyclic – formed from coalescing rings or

incomplete rings11. Pruritis – sensation that elicits desire to

scratch

Lichenoid

Milia

Poikiloderma

Polycyclic skin lesion: Erythema multiforme

Approach to the pt Advisable to asses the pt before taking

extensive history This way objective finding can be integrated

with relevant history 4 basic features must be noted:

1. Distribution of eruption2. The types of primary & secondary lesions3. Shape of individual lesions4. Arrangement of lesions

Examine skin, hair, nails, mucous membranes of mouth, eyes, nose, nasopharynx and anogenital region.

1st view pt from 4-6 ft for general character of skin and distribution of lesions.

Example When lesions are distributed on elbows,

knees & scalp, the most likely possibility based solely on distribution is psoriasis or dermatitis herpetiformis.

The primary lesion in psoriasis is a scaly papule that soon forms erythematous plaques covered with white scale, whereas that of dermatitis herpetiformis is an urticarial papule that quickly becomes a small vesicle.

History takingEmphasis on the following:1. Evolution of lesions

a) Site of onsetb) Manner in which the eruption spreadc) Durationd) Periods of resolution or improvement in

chronic eruptions

2. Symptoms associated with the eruptiona) Itching, burning, pain, numbnessb) Anything relieved the symptomsc) Time of day when symptoms most severe

3. Recent medications (prescribed + over the counter)

4. Associated systemic symptoms (malaise, fever, arthlagia)

5. Ongoing or previous illness6. h/o allergies7. Presence of photosensitivity8. Review of systems

9. Family history (melanoma, atopy, psoriasis, acne)

10. Social, sexual and travel history

Diagnostic techniques1. Skin Biopsy2. KOH preparation

KOH dissolves keratin Easy visualization of fungal elements Hyphae in dermatophye infection, pseudohyphae

and budding yeast in Candida3. Tzanck smear

For herpes virus infection (HSV or VZV) An early vesicle unroofed & the base scraped –

stain with Giemsa – mutinucleated epithelial cells seen

4. Diascopy Designed to asses whether skin lesion will blanch

on pressure To differentiate if a red lesion is hemorrhagic or

simply blood filled Urticaria will blanch on pressure while necrotising

vasculitis will not Performed by pressing a slide or a magnifying

lens against lesion5. Wood’s light

360 nm UV light by wood lamp1. Erythrasma (by Corynebacterium minutissimum)

looks coral pink2. Psudomonas colonisation apperas pale blue

3. Tinea capitis (by Microsporum cnis or M. audouni) exhibits yellow fluorescence

4. Freckles are accentuated bur postinflammatory hyperpigmentation fades

5. Vitiligo appears totally white6. Aslo aids in recognition of ash leaf spot in T.

sclerosis

6. Patch Test Testing sensitivity to specefic antigen Examined after a contact of 48hrs

Erythrasma

Tinea Capitis

Thank you