10.4 Recorded Lecture - Skin Conditions: Acne, Eczema, and Diaper Rash

Acne Vulgaris

• A common skin disease that affects 85% of individuals aged 12-25.
• Involves obstruction of follicles, which can be non-inflammatory or inflammatory.
• Non-inflammatory acne: Accumulated material obstructs and distends the follicle, thinning its walls.
• Inflammatory acne: Follicular wall ruptures, expelling sebum into the dermis and causing inflammation.
• Key factors: Follicular proliferation of gram-positive anaerobic bacteria, hyperkeratinization, excessive sebum production, follicle rupture.
• Treatment is individualized based on severity.

Atopic Dermatitis

• The most common cause of eczema in children.
• Cause involves genetic predisposition, altered skin barrier function, reduced ceramide levels, altered innate immunity, and altered immune responses to allergens, irritants, and microbes.
• Symptoms: Frequent exacerbations, severe pruritus, redness, edema, and scaly, dry, sensitive, and easily irritated skin.

Diaper Dermatitis

• Form of irritant contact dermatitis due to prolonged exposure to urine, ammonia, and feces.
• Maceration and friction from wet diapers or airtight plastic covers also contribute.
• Treatment: Frequent diaper changes, air exposure, super-absorbent diapers, and topical protection with petroleum and/or zinc oxide.

Impetigo

• Common bacterial skin infection in infants and children transmitted through direct and indirect contact.
• More prevalent in mid to late summer and in hot, humid climates, especially in crowded or unsanitary conditions.
• Bacterial invasion occurs through breaks in the skin or secondary infection of pre-existing dermatoses.
• Lesions are often located on the face, around the nose and mouth, must be differentiated from herpes simplex lesions.

Staphylococcal Scalded Skin Syndrome

• A serious staphylococcal infection mainly affecting children under five.
• Caused by virulent group two staphylococci producing an exfoliant toxin.

Tinea Capitis

• A fungal infection of the scalp.
• Primary microorganisms are found on cats, dogs, and rodents; human transmission is rare.
• Lesions are circular with broken hairs 1-3mm above the scalp, causing partial alopecia.
• Requires systemic treatment because topical antifungals cannot penetrate the hair follicle.

Tinea Corporis

• A superficial fungal infection common in children from contact with kittens and puppies.
• Affects non-hairy areas of the face, trunk, and limbs.
• Lesions are round or oval, scaling patches that spread peripherally with central clearing, creating a ring appearance from direct or indirect contact.

Thrush

• Presence of Candida in the mucous membranes of the mouth.
• Typically occurs in infants and immunocompromised individuals.

Molluscum Contagiosum

• Transmitted by skin-to-skin contact or autoinoculation.
• The pox virus induces epidermal cell proliferation and blocks immune responses.

Rubella (German Measles)

• A common communicable disease entering the bloodstream through the respiratory tract.
• Symptoms: Low-grade fever, headache, sore throat, runny nose, cough, and rash.
• Almost eliminated in the U.S. by vaccination.

Rubeola (Measles)

• A highly contagious acute viral disease transmitted by respiratory droplets.
• Symptoms: Fever, malaise, large lymph nodes, runny nose, conjunctivitis, and barking cough.

Varicella (Chickenpox) and Herpes Zoster (Shingles)

• Both caused by the varicella-zoster virus.
• Chickenpox lesions are vesicular and occur in the epidermis, eventually rupturing and crusting over.
• Complications from chickenpox are rare in children but more common in adults.
• Recovery from chickenpox provides almost complete immunity against future attacks.

Smallpox

• A highly contagious and deadly disease, preventable through vaccination.
• Eradicated worldwide in 1977, and routine vaccination has been discontinued.

Scabies

• Contagious disease caused by the itch mite colonizing the human epidermis transmitted by personal contact and infested items.
• Common in overcrowded or unsanitary areas.
• Mites burrow into the stratum corneum, laying eggs.
• Symptoms: Burrows, papules, and vesicles with severe itching, worsening at night.
• Bites occur in unexposed areas, resulting from sensitivity to the mite, its saliva, eggs, and feces.

Pediculosis (Lice)

• Highly contagious parasites that survive by sucking blood.
• Head and body lice spread through direct personal contact or indirectly via shared items.

Fleas

• Wingless, jumping insects that feed on blood.
• Bites from cats, dogs, and humans are common.
• Flea bites can transmit plague, tularemia, and cat scratch disease.

Bedbugs

• Bloodsucking parasites living in crevices and cracks of floors, walls, furniture, and bedding.

Cutaneous Hemangiomas

• Benign tumors from rapid growth of endothelial cells, forming extra blood vessels.
• Can be superficial or deep.
• Strawberry hemangiomas resolve by 5-9 years old, usually without scarring.
• Superficial hemangiomas typically require no treatment.

Cutaneous Vascular Malformations

• Rare congenital anomalies of blood vessels present at birth.
• Classified as low flow or high flow
• Low flow: capillaries, veins, and lymphatics.
• High flow: arteriovenous malformations.