An Overview of Skin Disorders in Primary Care

Vocabulary flashcards covering basic functional anatomy, primary and secondary skin lesions, diagnostic tools, and key dermatological disorders based on the lecture slides.

Epidermis

An avascular stratified squamous epithelium, firmly attached by the complex basement membrane to the dermis.

Basement Membrane

A structure that acts as an anchor for the epidermis, allowing free movement of cells and nutrients between the dermis and epidermis.

Dermis

A vascular layer of skin that supports the epidermis structurally and nutritionally, varying in thickness from $1\,m$ on the face to $4\,mm$ on the back.

Langerhans Cells

Dendritic, bone-marrow derived cells constituting $5\%$ of epidermal cells that function in immune surveillance and presentation of foreign antigens to T-lymphocytes.

Melanocytes

Cells of neural crest origin located mainly in the basal layer of the epidermis that synthesize melanin from tyrosine.

Sebaceous Glands

Epidermal appendages arising from hair follicles that discharge sebum into the upper part of the follicle under hormonal control, mainly testosterone.

Apocrine Glands

Sweat glands found in the axillae, perineum, genitalia, and areolae that become functional after puberty under testosterone and are innervated by sympathetic adrenergic fibres.

Eccrine Sweat Glands

Sweat glands found everywhere on the skin surface with ducts opening directly to the surface, functioning in thermoregulation and innervated by sympathetic cholinergic fibres.

Macule

A small, non-palpable area of altered skin colour.

Papule

A palpable elevation of the skin measuring less than $0.5\,cm$.

Plaque

A palpable, flat-topped, discoid lesion measuring greater than $2\,cm$.

Nodule

A solid, palpable lesion located within the skin measuring greater than $0.5\,cm$.

Vesicle

A small fluid-filled blister measuring less than $0.5\,cm$.

Bullae

Large fluid-filled blisters measuring greater than $0.5\,cm$.

Pustule

A blister containing pus.

Wheal

An elevated skin lesion often caused by dermal edema.

Telangiectasia

Visible dilatation of superficial blood vessels.

Petechiae

Pin-sized macules of blood.

Burrow

A linear or curved papule caused by the burrowing scabies mite.

Comedone

A dark horny keratin and sebaceous plug within pilo-sebaceous openings.

Scale

A secondary skin lesion consisting of a flake from the horny layer.

Crust

A secondary skin lesion formed by dried exudate, blood, or serous fluid.

Excoriation

An erosion typically caused by scratching.

Lichenification

Thickening of the epidermis characterized by exaggerated skin markings.

Erosion

Partial loss of the epidermis.

Ulcer

A lesion where at least the full thickness of the epidermis is lost.

Keloid

A benign, excess or abnormal scar formation.

Striae

Atrophic pink or white linear lesions caused by changes in connective tissue.

Wood's Light

A diagnostic light that causes Microsporum canis to appear green and Corynebacterium minutissimum to appear pink.

Psoriasis

A chronic, recurrent, inherited, non-infectious skin disease caused by an abnormally fast turnover of the epidermis.

Erythrasma

A bacterial skin disease caused by Corynebacterium minutissimum.

Von Recklinghausen's Disease

Another name for Neurofibromatosis, classified under phakomatoses.