Classification of Dermatoses

Simplified Dermatology Classification Guide

Infectious Dermatoses

Key Points: Caused by bacteria, viruses, fungi, or parasites. Often contagious; treat with antimicrobials. Look for symptoms like redness, pus, or itch. Added more common examples for quick reference.

Type	Key Examples
Bacterial	Impetigo: Honey-colored crusts; highly contagious in kids (Staph/Strep). Cellulitis: Red, swollen, warm skin; spreads quickly. Leprosy: Skin lesions and nerve damage (Mycobacterium leprae). Erysipelas: Raised, sharp-bordered rash (Strep). Folliculitis: Pimple-like bumps around hair follicles. Furuncle (Boil): Painful pus-filled lump; deeper infection. Carbuncle: Cluster of boils; more severe.
Viral	Herpes Zoster (Shingles): Painful rash in one area; from chickenpox virus. Warts: Rough growths (HPV); common, plantar, flat types. Molluscum Contagiosum: Pearly bumps with central dimple. Herpes Simplex: Cold sores or genital blisters. Varicella (Chickenpox): Itchy blisters all over body. Hand-Foot-Mouth Disease: Blisters on hands, feet, mouth (Coxsackie virus).
Fungal	Tinea Capitis: Scaly scalp patches with hair loss (kids). Candidiasis: Red, moist rash in folds; yeast overgrowth. Onychomycosis: Thick, discolored nails. Tinea Corporis (Ringworm): Circular, scaly rings on body. Tinea Pedis (Athlete's Foot): Itchy, cracked feet. Tinea Versicolor: Light/dark patches on trunk (yeast).
Parasitic	Scabies: Itchy burrows in skin folds (mites). Cutaneous Larva Migrans: Winding red tracks (hookworms). Pediculosis: Lice on head/body/pubic area; nits on hair. Leishmaniasis: Skin sores from sandfly bites (protozoa). Bedbug Bites: Itchy red welts in lines or clusters.

Non-Infectious Dermatoses

Key Points: Not contagious; often from immune issues, genes, or environment. Manage with topicals or systemic meds. Expanded examples for better understanding.

Category	Key Examples
Inflammatory / Allergic	Atopic Dermatitis (Eczema): Itchy, red, scaly skin; common in kids with allergies. Contact Dermatitis: Rash from irritants/allergens (e.g., poison ivy, nickel). Urticaria (Hives): Itchy welts from allergies or stress. Seborrheic Dermatitis: Flaky scalp (dandruff) or face rash. Angioedema: Deep swelling, often with hives.
Autoimmune	Pemphigus Vulgaris: Blisters that break easily; mouth sores common. Cutaneous Lupus Erythematosus: Sun-sensitive rashes; butterfly face rash. Dermatomyositis: Purple eyelids, knuckle rashes; muscle weakness. Bullous Pemphigoid: Tense blisters in elderly. Scleroderma: Skin thickening and tightening. Vitiligo: Loss of skin pigment in patches.
Papulosquamous	Psoriasis Vulgaris: Thick, scaly plaques on elbows/knees. Lichen Planus: Purple, itchy bumps; white lines inside. Pityriasis Rosea: Herald patch followed by trunk rash. Pityriasis Rubra Pilaris: Red-orange scaly plaques; palm/sole involvement. Parapsoriasis: Patchy, scaly rashes resembling psoriasis.
Neoplastic	Basal Cell Carcinoma (BCC): Pearly bump; sun-exposed areas. Malignant Melanoma: Irregular mole; ABCDE rule. Actinic Keratosis: Rough, scaly spots from sun damage. Squamous Cell Carcinoma (SCC): Crusted or ulcerated growths. Kaposi's Sarcoma: Purple plaques; associated with HIV. Seborrheic Keratosis: Benign "stuck-on" warts in older adults.

Lesion Classification

Key Points: Primary: New lesions. Secondary: Evolved from primary or trauma. Use for quick diagnosis. Added more examples and simplified descriptions.

Type	Common Lesions	Quick Description & Examples
Primary Lesions	Macule/Patch Papule/Plaque Vesicle/Bulla Pustule Nodule Wheal Cyst	Macule/Patch: Flat color change (small/large). E.g., Freckles, vitiligo, cafe-au-lait spots, port-wine stain, Mongolian spots. Papule/Plaque: Raised solid bump (small/large). E.g., Acne, warts, psoriasis plaques, lichen planus, insect bites. Vesicle/Bulla: Fluid-filled (small/large). E.g., Herpes, chickenpox, pemphigus, burns, friction blisters. Pustule: Pus-filled. E.g., Acne, folliculitis, impetigo, candidiasis, rosacea. Nodule: Deep solid mass. E.g., Rheumatoid nodules, lipoma, erythema nodosum. Wheal: Edematous plaque. E.g., Hives, allergic reactions. Cyst: Encapsulated fluid/semi-solid. E.g., Sebaceous cyst, epidermoid cyst.
Secondary Lesions	Scale Crust Erosion/Ulcer Fissure Scar Atrophy Lichenification Excoriation	Scale: Flaky skin. E.g., Psoriasis, eczema, tinea, ichthyosis. Crust: Dried pus/blood. E.g., Impetigo, herpes, scabs from wounds. Erosion/Ulcer: Loss of skin (shallow/deep). E.g., Pemphigus, venous ulcers, bedsores, syphilitic chancre. Fissure: Linear crack. E.g., Hand eczema, angular cheilitis, anal fissures. Scar: Fibrous tissue. E.g., Post-acne, burns, keloids, hypertrophic scars. Atrophy: Thinning. E.g., Steroid use, aging, striae, morphea. Lichenification: Thickened skin. E.g., Chronic eczema, prurigo nodularis. Excoriation: Scratch marks. E.g., From itching in atopic dermatitis, neurotic excoriations.

Additional Classification Schemes

Key Points: Classify by layer, time, location, or age for better diagnosis. Added more examples and sub-points for clarity.

Basis	Types & Key Examples
By Skin Layer	Epidermal: Top layer issues. E.g., Psoriasis, eczema, warts, actinic keratosis, tinea versicolor, ichthyosis. Dermal: Middle layer. E.g., Granuloma annulare, urticaria, keloids, morphea, dermatofibroma, sarcoidosis. Subcutaneous: Fat layer. E.g., Erythema nodosum, lipomas, panniculitis, lupus profundus, cellulite infections. Appendageal (Hair/Nails/Glands): E.g., Acne (sebaceous), alopecia areata (hair), onychomycosis (nails).
By Duration	Acute: Quick onset/short. E.g., Hives, contact dermatitis, shingles, cellulitis, drug rashes, sunburn. Chronic: Long-term. E.g., Psoriasis, eczema, lichen planus, lupus, vitiligo, rosacea. Chronic-Relapsing: Flares/remissions. E.g., Pemphigus, herpes simplex, hidradenitis, chronic urticaria, gouty tophi.
By Distribution	Localized: One spot. E.g., BCC, shingles, lichen simplex, pyogenic granuloma, nevus, trauma-related. Generalized: Whole body. E.g., Pityriasis rosea, measles, drug eruptions, psoriasis guttate, scarlet fever. Specific Patterns: Flexural: Eczema, intertrigo, inverse psoriasis, candidiasis. Extensor: Psoriasis, granuloma annulare, myxedema. Photodistributed: Lupus, PMLE, phototoxic drugs, porphyria. Dermatomal: Shingles, neuralgia-related.
By Age Group	Neonatal/Infantile (0-2): E.g., Neonatal acne, cradle cap, diaper rash, hemangiomas, milia, erythema toxicum. Pediatric (2-12): E.g., Eczema, molluscum, warts, ringworm, impetigo, HSP, Kawasaki disease. Adolescent/Adult (13-65): E.g., Acne, psoriasis, STIs, contact dermatitis, melanoma, occupational rashes. Geriatric (>65): E.g., Skin cancer, pemphigoid, stasis dermatitis, xerosis, senile purpura, shingles.