Skin condition library

Melanoma

The most dangerous skin cancer - but 99% survival when caught early. Learn the ABCDE signs.

Basal Cell Carcinoma

The most common cancer in humans. Slow-growing, rarely spreads, but can cause serious tissue damage if untreated.

Squamous Cell Carcinoma

Second most common skin cancer. More aggressive than BCC - can spread to lymph nodes if not treated early.

Merkel Cell Carcinoma

Rare but highly aggressive. Appears as a painless, fast-growing, firm nodule - often flesh-colored or bluish-red.

Kaposi Sarcoma

Purplish lesions caused by HHV-8, most commonly in immunocompromised individuals.

Sebaceous Carcinoma

Arises from oil glands, most often on the eyelid. Frequently misdiagnosed as a chalazion or stye.

Angiosarcoma

Rare cancer of blood or lymph vessels. Often appears as a bruise-like patch on the scalp of elderly patients.

Cutaneous Lymphoma

Cancer of immune cells affecting the skin. Early stages look like eczema or psoriasis, making diagnosis difficult.

Dermatofibrosarcoma Protuberans

Rare slow-growing tumor of the dermis. Looks like a firm plaque or nodule on the trunk - low metastatic potential but high local recurrence.

Lentigo Maligna

The earliest stage of a specific melanoma type. A slowly expanding flat brown patch on sun-damaged facial skin.

Actinic Keratosis

Rough, sandpaper-like patches from years of sun damage. The most common precancer - 5-10% progress to squamous cell carcinoma.

Dysplastic Nevus

Atypical moles with irregular features. The single strongest visual risk marker for melanoma.

Bowen's Disease

Early-stage SCC confined to the top skin layer. A persistent, well-defined red scaly patch - 3-5% progress to invasive cancer.

Leukoplakia

Persistent thick white patches in the mouth that cannot be scraped off. 3-17% risk of oral cancer.

Cutaneous Horn

Hard cone-shaped keratin projection. The horn is harmless - but 16% hide cancer at the base.

Keratoacanthoma

Rapidly growing dome-shaped nodule with a central crater. Most dermatologists treat it as low-grade SCC.

Erythroplasia

Bright red velvety plaque in the mouth. Over 50% harbor cancer at diagnosis - the most dangerous oral precancer.

Atypical Fibroxanthoma

Low-grade tumor on severely sun-damaged skin. Typically the scalp of elderly men. Excellent prognosis with excision.

Porokeratosis

Ring-like lesions with a distinctive raised ridge border. 7-11% lifetime SCC risk.

Common Nevus

Normal moles - clusters of pigment cells. Usually harmless, but monthly monitoring for changes is essential.

Seborrheic Keratosis

Waxy, stuck-on growths - the most common benign tumor in adults over 50. Harmless but frequently mistaken for melanoma.

Cherry Angioma

Bright red blood vessel growths. Extremely common after 30, completely harmless, no treatment needed.

Dermatofibroma

Firm, small brown bump - usually on the legs. Harmless. The dimple sign is its signature feature.

Lipoma

Soft, rubbery fatty lump under the skin. The most common soft tissue tumor - almost always harmless.

Epidermoid Cyst

Slow-growing, round, skin-colored lump filled with keratin. Benign but can become painfully infected.

Skin Tag

Small, soft, hanging pieces of skin. Extremely common in skin folds - completely harmless.

Pyogenic Granuloma

A rapidly growing, bright red, easily bleeding bump. Looks alarming but is benign - name is misleading (not infectious).

Solar Lentigo

Flat brown spots from cumulative sun exposure. Completely harmless - but sometimes confused with lentigo maligna (early melanoma).

Milium

Tiny white bumps on the face filled with keratin. Extremely common in newborns and adults. Harmless.

Blue Nevus

A blue or blue-black mole caused by deep pigment cells. Stable and benign - but can mimic melanoma.

Halo Nevus

A mole surrounded by a white ring of depigmented skin. The immune system attacking the mole - usually benign, most common in teenagers.

Spitz Nevus

A dome-shaped pink or brown mole common in children. Can closely resemble melanoma under the microscope - often excised for certainty.

Xanthelasma

Yellowish cholesterol plaques on the eyelids. Benign but may signal high blood lipids - worth checking.

Clear Cell Acanthoma

Rare, benign red-brown nodule on the lower legs. Slow-growing with a distinctive wafer-like scale pattern.

Psoriasis

Chronic autoimmune condition causing thick, silvery scaly patches. Affects 2-3% of the population. Not contagious.

Eczema

Red, itchy, inflamed skin - the most common chronic skin condition in children. Part of the atopic triad with asthma and hay fever.

Rosacea

Chronic facial redness, visible blood vessels, and sometimes bumps. Common triggers: heat, alcohol, spicy food, stress.

Vitiligo

Autoimmune destruction of pigment cells creating white patches. Affects 1-2% of people worldwide. Not contagious.

Melasma

Brown or gray-brown facial patches triggered by hormones and sun. Extremely common in women during pregnancy or on birth control.

Acne Vulgaris

The most common skin condition worldwide - affects 85% of teenagers. Caused by clogged pores, bacteria, hormones, and inflammation.

Folliculitis

Infected or inflamed hair follicles causing red, tender bumps. Common from shaving, tight clothing, or hot tubs.

Urticaria

Raised, itchy welts that appear suddenly. Usually from allergic reactions, stress, or infections. Most cases resolve within 24 hours.

Impetigo

Highly contagious bacterial skin infection in children. Causes honey-colored crusted sores that spread by touch.

Ringworm

Fungal infection - not a worm. Creates circular red patches with clearing centers. Contagious but easily treated.

Molluscum Contagiosum

Viral infection causing small, firm, dimpled bumps. Extremely common in children. Usually self-resolving.

Shingles

Painful blistering rash in a band on one side of the body. Caused by reactivation of the chickenpox virus. Vaccine available.

Lichen Planus

Purplish, flat-topped, itchy bumps - the five Ps: Pruritic, Purple, Polygonal, Planar, Papules.

Scabies

Intensely itchy rash from microscopic burrowing mites. Worse at night. Spreads through prolonged skin contact.

Perioral Dermatitis

Red, bumpy rash around the mouth and nose - often triggered by topical steroids. Common in women aged 20-45.