Skin Diseases for Science Olympiad Anatomy/Physiology 2025

Melanoma

-melanocytes

-dark spots not necessarily in sun-exposed areas

-ABCDE

-most deadly form of skin cancer (spreads quickly)

basal cell carcinoma

-basal cells (bottom of epidermis)

-shiny, raised, flesh-colored, umbilicated bumps usually on sun-exposed areas

-often blood vessels running through

-rarely metastasizes

-surgery for treatment

squamous cell carcinoma

-firm bump (nodule) on the skin (often in sun-exposed areas)

-scaly crust

-surgery for treatment

Kaposi's sarcoma

-lining of blood/lymph vessels

-dark (pink, purple, brown) skin lesions usually face, arms, legs

-caused by HHV 8

-4 types: AIDS-related, iatrogenic (like in organ transplants), classic (older European/Middle Eastern men), endemic (young people in Africa)

Merkel cell carcinoma

-merkel cells (base of epidermis, connected to nerves)

-flesh-colored or bluish-red nodule

-often on face, head, or neck

-Merkel cell polyomavirus

-surgery, radiation therapy, etc for treatment

psoriasis

-immune problem that causes skin cells to grow faster than usual

-rash with itchy, scaly patches

-knees, elbows, trunk, scalp

-cyclic rashes that flare up then subside

-most common type: plaque psoriasis

-treatment: topical steriods, vitamin, D, retinoids, etc

contact dermatitis

-itchy rash caused by direct contact with a substance or an allergic reaction to it

-steroid creams/ointments for treatment

atopic dermatitis (eczema)

-chronic condition that causes dry, itchy, and inflamed skin

-common in young children

-can flare up and then clear cyclically

-genetic basis or too much staphylococcus aureus

-treat by moisturizing skin + medicated ointments

chickenpox

-itchy rash with small, fluid-filled blisters

-fever, loss of appetite, headache tiredness

-caused by varicella zoster virus

-mild in healthy children, serious in adults

-vaccine exists

shingles

-reactivation of the varicella zoster virus stored in nerves

-painful rash at dermatome

-red base, blisters, pain

-can also have headache, fatigue, light sensitivity

-vaccine exists (Shingrix)

-antivirals (acyclovir, valacyclovir, etc) for treatment

Hansen's disease (leprosy)

-caused by Mycobacterium leprae and Mycobacterium lepromatosis

-symptoms affect skin, nerves, lining of the nose

-discolored skin, nodules, ulcers, swelling, loss of eyebrows

-loss of sensation in affected areas can occur

-antibiotics for treatment

cellulitis

-bacterial skin infection (strep, staph)

-affect skin swollen, inflamed, painful, warm to the touch

-goes to subcutaneous fat

-borders less defined

-usually affects lower legs, but can also occur on arms, face, etc

-antibiotics for treatment

erysipelas

-caused by group A strep

-goes partially through dermis

-well-demarcated borders

-affects children + adults

-red skin

-antibiotics for treatment

impetigo

-stratum corneum

-kids aged 2-6

-strep/staph

-pus-filled blisters/pustules oozing honey-colored liquid, yellowish scabs

-face, arms, legs

-often caused by insect bite getting infected

-antibiotics for treatment

athlete's foot

-tinea pedis (fungus)

-peeling, itchy feet

-treat with topical anti-fungals

carbuncles

"carload of boils"

boils

inflammation of hair follicles and sebaceous glands

HPV

-causes warts (genital, common, plantar, flat)

-sexual or skin-to-skin transmission

-can cause cervical/anal cancer

sunburn

redness of the skin caused by exposure to the rays of the sun

first-degree burn

Superficial burns through only the epidermis.

second-degree burn

A partial-thickness burn involving the epidermis and the dermis.

third-degree burn

a burn involving all layers of the skin; characterized by the destruction of the epidermis and dermis, with damage or destruction of subcutaneous tissue