INTEGUMENTARY DISORDERS (slides 74-finish) - APRIL 1st

Focusing on the underlying cause of skin disorders is crucial for effective treatment.

Psoriasis
- A systemic disorder that manifests on the skin.
- Characterized by:
- Plaques: Scaly white lesions that can appear anywhere on the body.
- Symptoms: Itching, dryness, cracks, bleeding, possible infections.
- Nature: Autoimmune condition leading to systemic inflammation and joint pain (arthralgia).
- Long-term Effects: Can cause organ damage due to excessive inflammation.
- Treatment: Autoimmune suppressants.

Description: Both inflammatory and autoimmune.
Characteristics:
- Manifestation includes a distinct butterfly rash on the nose and cheeks.
- Rash may also appear on the scalp, leading to alopecia.

Most common bacterial skin infection.
Causes:
- Surge of hormones during puberty stimulates sebaceous glands.
- Overproduction of sebum, leading to clogged hair follicles.
- Infected sebum leads to pustules.

Can manifest as:
- Mild cases: Occasional pimples.
- Severe cases: Painful lesions or cysts.
Common causative bacteria: Staphylococcus aureus.
Symptoms:
- Comedones: Non-inflammatory lesions (whiteheads and blackheads).
- Pustules: Inflammatory lesions (painful, can lead to scarring).
- Increased risk in: Men due to higher testosterone levels; women with conditions like PCOS.
Treatment:
- Over-the-counter topical agents: Benzoyl peroxide, salicylic acid, Differin gel (vitamin A derivative).
- Systemic treatments for severe cases: Tetracyclines (like minocycline or doxycycline), topical erythromycin, dapsone gel.
- Birth control pills for hormonal regulation in women; microdermabrasion for exfoliation.

Description: Infection of the dermis and subcutaneous tissue, typically caused by Staphylococcus or Streptococcus.
Characteristics:
- Often follows trauma (skin barrier breach).
- Commonly appears in lower extremities, may be severe in diabetic patients.
- Signs: Redness, swelling, heat; may spread leading to more severe conditions (marking redness can help track spread).
Treatment:
- Hospitalization for severe cases (e.g., diabetics) with IV antibiotics; oral antibiotics for mild cases.
Contagiousness: Not contagious as the infection is deep within the skin.

Description: Contagious bacterial infection, often caused by Staphylococcus or Group A streptococci.
Symptoms:
- Starts as red lesions near the mouth, oozes yellow fluid, crusts over.
- Highly contagious; spreads through direct and indirect contact (towels, bedding).
Treatment: Topical antibiotics for simple cases, systemic antibiotics if it escalates.
Symptoms: Itching can lead to spreading through scratching.

Description: Severe “flesh-eating” bacterial infection.
Causes:
- Mix of aerobic and anaerobic bacteria, often stemming from Group A streptococci.
Characteristics:
- Rapid spread, severe pain, and systemic symptoms (fever, hypotension).
- High mortality and disability rates; often requires aggressive treatment, including surgical debridement or amputation.
Risk Factors: Trauma, chronic illnesses, compromised immune system.

Types: Type 1 (cold sores) and Type 2 (genital herpes).
Typical presentation: Tingling or burning sensations precede lesions.
Transmission: Direct contact, can remain dormant in trigeminal nerve.
Treatment: Antivirals like Abreva to minimize symptoms; the virus cannot be eliminated.

Pathophysiology: Varicella (chickenpox) virus reactivates as shingles, usually along nerve endings.
Symptoms: Painful blisters in localized areas, associated with nerve pain (post-herpetic neuralgia).
Contagiousness: Shingles cannot be transmitted, but can cause chickenpox in unvaccinated individuals.
Vaccination: Shingles vaccine strengthens the immune response to prevent reactivation.

Description: Rare skin cancer related to HIV/AIDS.
Causes: Infection with human herpes virus-8 (HHV-8).
Symptoms: Appears as purplish marks on the skin, representing proliferation of endothelial cells.

Causes: Electrical shock, heat, radiation, chemicals.
Immediate threat: Loss of fluid leading to dehydration, electrolyte imbalances, and hypotension.
Can lead to renal failure and circulatory shock, especially critical if burns exceed certain percentages or locations.

First-degree burns: Affect epidermis; red and painful but heal within days, no scarring.
Second-degree burns: Affect epidermis and upper dermis, characterized by blisters; heal within weeks, no scarring.
Third-degree burns: Affect all layers, no pain initially due to nerve destruction, severe risk of infection, often require skin grafting.

Critical conditions: Require IV fluids, electrolyte management, high-calorie diets (proteins and fats).
Prophylactic antibiotics to prevent infection, debridement of necrotic tissue, and potential skin grafts.

Description: Life-threatening conditions that cause skin to separate from the dermis.
Mechanism: Triggered by hypersensitivity to certain drugs, causing apoptotic cell death in the epidermis.
Classification: Less than 10% body surface area affected is Stevens-Johnson; more than 30% is TEN.
Drugs associated with SJS/TEN: Lamotrigine, sulfonamides (e.g., Bactrim), allopurinol, certain NSAIDs.
Treatment: Immediate discontinuation of causative drug, similar to burn treatment (fluid replacement, antibiotics, skin grafts).