Skin Pathology

Some T cells selectively home to skin by virtue of homing receptors called Cutaneous Lymphocyte Antigen (CLA)

Epidermis contains intra epithelial lymphocytes including Gamma / Delta cells

Macule

Papule

Nodule

Plaque

Vesicle

Bulla

Pustule

Scale

Lichenification

Excoriation

Hyperkeratosis

Parakeratosis

Acanthosis

Dyskeratosis

Acantholysis

Papillomatosis

Lentiginous

Spongiosis

Acute inflammatory Dermatoses

In Acute – mononuclear cells than neutrophils due to their limited course of their natural history

Urticaria – more common between 20 – 40 yrs

Lesions usually exists for less than 24 hrs Pruritc papule to large edematous plaques

Acute Eczematous dermatitis

Eczema – red , papulo vesicular oozing crested lesion

Later they can develop into raised scaling plaques

Most common form is contact dematitis Spongiosis ossurs So called spongiotic dermatitis

Erythema multiforme

Self limited Hypersensitivity to drugs / infections Drubs – sulphonamides , penicillins , salycylates Infection – HSV , mycoplasma , Fungal infections – Histoplasma Capsulatum and

Coccidiodes imitis Multiform lesions –

1. Targetoid lesion – Red papule or macule with a pale vesicular or eroded centre

2. Papules , macules ,vesicles ,bullae

Chronic inflammatory Dermatoses

1. Psoriasis

2. Lichen Planus

3. Lichen simplex Chronicus

Tumors of skin epithelium

Benign and Premalignant

1. Seborrhic keratitis

2. Sebaceous adenoma

3. Actinic keratitis

Malignant

1. Squamous cell carcinoma

2. Basal cell carcinoma

Tumors of melanocytes

Benign

1. Melanocytic nevi

Malignant

1. Melanoma

Malignant Melanoma