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Secondary lesions

- Secondary lesions is an eruption that occurs secondarily after a primary or

other skin lesions.

 Types:

Atrophy

  Skin becomes thin or has a smooth or nely wrinkled surface

secretory function is reduced, and the skin surface dries.

Aging leads to skin atrophy, including subcutaneous lipoatrophy, striae

atrophicae caused by steroids (hapter !"#, kraurosis $ul$ae and macular

atrophy.

Scaling

Abnormal thickening of the skin surface and formation of scaly white lamellae

  Desquamation is the detachment of scales from the skin surface

%ine scaling is called pityriasis& larger scaling is called large lamellar

scaling& thick sil$er-gray scales are called micaceous scales, $isible in

psoriasis and sh-scale-like large scaling, are called ichthyosiform scales  There are two mechanisms of scale formation:

-   Retention hyperkeratosis: such as in ichthyosis, horny cell layers are

too cohesi$e to e'foliate normally& they e'foliate only after accumulating

abnormally.- n proliferation hyperkeratosis, such as in psoriasis, the epidermis

e'foliates abnormally from o$er-proliferation. )listers and pustules may

become scales secondarily.

Crust

Solidied keratin and e'udate that forms on an erosion or on ulcerous skin

A crust of clotted blood is called a bloody crust (commonly called a scab#

Callus (tylosis)

locali*ed, proliferated, and thickened epidermal horny cell layers

commonly called a corn

Claus

the horny cell layer becomes wedged into the skin by prolonged physical

stimulation, such as pressure produced by wearing shoes for long periods of time

Scar! keloid

t is the reacti$e proliferation of dermal collagen after the skin is in+ured (%ig.

.!#. ealing usually lea$es a /at scar

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Sometimes the scar is hypertrophic, or thickened, but conned to the

margin of the wound. Starts some time after the in+ury and e'tends beyond the wound site

"#coriation

t is partial damage to the epidermis by in+ury or rubbing

 The symptoms $ary by the depth of e'coriation.

0hen it occurs within the horny cell layer, it heals by scaling. 0hen it occurs

in a deeper site, blood or other /uids may be e'uded. ealing is without scarring.

"rosion

t is epidermal e'coriation down to the basal cell layer. t often de$elops after

breakage of a blister or pustule appears red and is inltrated with serous /uid in most cases

fre1uently forms in the lips and oral mucosa, from their lack of keratinocytes ealing is without scarring

t fre1uently occurs in diseases that cause intraepidermal blistering, such as

impetigo contagiosa, pemphigus, epidermolysis bullosa and herpes simple',

and in diseases that cause subepidermal blistering, such as pemphigoid,

burns and spontaneous intensely itchy eruptions

$lcer

t is the complete deciency of tissue at sites deeper than erosion, reaching

from the dermis to subcutaneous tissues

n healing, an ulcer is repaired by granular tissue and scarring is left. Thebottom of an ulcer often has bleeding, serous e'udation, and a crust that

includes part of the pre$ious lesion. 2lceration occurs secondarily in many cases after blood circulation disorder

%issure

t is a thin linear clea$age running through the deep epidermal layer and the

dermis t is commonly called a crack  

t may accompany another lesion, including chronic ec*ema in the hands and

feet, psoriasis and angular