Structure and Function of Skin and Associated Diseases

Flashcards covering the structure and function of skin, skin-associated diseases, infectious diseases, and treatment methodologies.

Stratum corneum

The outermost layer of skin, containing keratin, a waterproofing protein layer, and dead cells.

Epidermis

The thin outer portion of skin, composed of layers of epithelial cells.

Dermis

The inner, thick portion of skin, composed mainly of connective tissue.

Sweat components

Contains salts, lysozyme, and antimicrobial peptides that inhibit microbes.

Sebum

An oily secretion containing fatty acids that inhibit pathogens.

Normal skin microbiome property

Resistant to drying and high salt concentration.

Skin microbiome

Contains two genuses of gram-positive cocci: Staphylococci and Micrococci.

Areas with higher moisture

Regions such as armpits have higher populations of skin microbiomes.

Function of Propionibacterium acnes

Inhabits hair follicles, metabolizing sebum and producing acids that maintain low skin pH.

Cause of dandruff

Malassezia furfur (yeast) grows on oily skin secretion.

Common causes of skin infections

Staphylococcus and Streptococcus species.

Staphylococcus infections

Form irregular clusters and many produce coagulase.

Coagulases

Enzymes that clot fibrin in blood, inducing blood clots.

Properties of Staphylococcus aureus

Carried in nasal passages, golden-yellow colonies, coagulase-positive, may produce toxins.

MRSA

Methicillin Resistant Staphylococcus aureus strains resistant to penicillin-like antibiotics.

Folliculitis

Infection of hair follicles caused by Staphylococcus aureus.

Symptoms of toxic shock syndrome

Fever, vomiting, shock, and organ failure caused by TSST-1.

Exfoliative toxins

Proteases that digest connective proteins in skin, causing peeling.

Virulence factors of Group A streptococci

Include streptolysins, M proteins, hyaluronidase, and streptokinases.

Erysipelas

S. pyogenes infects the dermal layer of skin, causing tissue destruction.

Pseudomonas aeruginosa

Gram-negative, aerobic rod; causes opportunistic infections and is resistant to many antibiotics.

Acne

Caused by blockage of hair follicles by skin cells and sebum.

HPV

Human papillomavirus that causes warts.

Variola virus

Orthopoxvirus that causes smallpox, transmissible via respiratory route.

Properties of Chickenpox

Caused by herpesvirus varicella-zoster, transmitted via respiratory route.

Reye's syndrome

Severe complication of chickenpox characterized by vomiting and brain dysfunction.

Properties of shingles

Reactivation of varicella-zoster virus with limited distribution along sensory nerves.

HSV-1 and HSV-2

Herpes simplex viruses primarily causing oral and genital infections.

Herpetic whitlow

Vesicles and blisters on fingers caused by HSV-1.

Symptoms of measles

Cold-like symptoms, macular rash, and Koplik's spots.

Rubella transmission

Transmitted via respiratory route with macular rash and light fever.

Lymphangitis

Inflamed lymph vessels visible as red streaks under skin, a sign of septicemia.

Septicemia

Acute illness due to pathogens or their toxins in blood.

Endocarditis

Inflammation of the endocardium, often caused by Staphylococcus aureus.

Anthrax

Caused by Bacillus anthracis, which forms endospores.

Cutaneous anthrax

Occurs through minor cuts with 20% mortality rate without treatment.

Gastrointestinal anthrax

Ingested from contaminated food with more than 50% mortality rate.

Inhalational anthrax

Inhalation of endospores leading to near 100% mortality rate.

Dengue fever

Caused by a virus transmitted by mosquitoes, with severe cases resulting in bleeding.

Zika Virus transmission

Primarily through Aedes mosquitoes, with risk of congenital defects.

Toxoplasmosis

Caused by Toxoplasma gondii, transmitted through contact with cat feces or undercooked meat.

Malaria transmission

Caused by Plasmodium species transmitted by mosquito bite.

Shigellosis

Infection caused by Shigella flexneri that produces Shiga toxin.

Salmonellosis

Caused by Salmonella enterica, often associated with undercooked poultry.

Cholera

Caused by Vibrio cholerae, which produces cholera toxin leading to severe dehydration.

Staphylococcal Enterotoxicosis

Food poisoning caused by exotoxins from Staphylococcus aureus.

Campylobacter Gastroenteritis

Commonly caused by Campylobacter jejuni in poultry.

Clostridium difficile Associated Diarrhea

Often linked to antibiotic use, treated with specific antibiotics.

Hepatitis B treatment

Prevented by vaccine; treated with interferons.

Hepatitis C treatment

No vaccine; treated with RNA-dependent RNA polymerase inhibitors.

Rotavirus effects

Common in children, causes diarrhea and vomiting.

Norovirus

Highly contagious with fecal-oral transmission causing gastroenteritis.

Zika virus diagnosis

Utilizes reverse transcriptase PCR due to single-stranded RNA genome.

Septic shock mechanism

Inflammatory cytokine release causes decreased blood pressure.

Gram-negative sepsis agents

Commonly caused by Klebsiella spp., E. coli, and Pseudomonas aeruginosa.

Meningitis symptoms

Fever, headache, stiff neck, nausea, vomiting, possible coma.

Tetanus causative agent

Caused by Clostridium tetani, leading to muscle spasms.

Botulism properties

Caused by Clostridium botulinum, results from toxin ingestion.

Lyme disease diagnosis

Utilizes ELISA and fluorescent-antibody tests.

Viral Alpha and Beta properties

Detected through specific immune serum tests.

Vesicular stomatitis virus

Primarily infects livestock, causing flu-like symptoms in humans.

TorCH test meaning

Tests negative means no congenital virulence pathogens detected.