SCIED 3B Group 7 (Chapter 9 - Microbial Diseases of the Skin and Eyes) PPT

"Empowering Skin Health." Date and Time aimed at understanding microbial diseases in skin health.

Definition of Microbial Skin DiseasesInfections from bacteria, fungi, viruses invading skin lead to symptoms like redness, itching, swelling, lesions.

Bacterial Diseases OverviewTwo Main Groups of Bacteria:Streptococcus: Gram-positive cocci, catalase-negative, often hemolytic.Staphylococcus: Gram-positive cocci, catalase-positive.Both groups have important roles in infections and are common on mucous membranes.

Types of Skin LesionsVesicles: Small, fluid-filled lesions.Bullae: Large vesicles greater than 1 cm.Macules: Flat, reddened lesions.Papules: Raised lesions; pustules when containing pus.

Specific Bacterial DiseasesStaphylococcus epidermidis: Coagulase-negative, found commonly on skin.Staphylococcus aureus: Coagulase-positive, pathogenic strain isolated from infected patients.

Coagulase-Positive and Coagulase-Negative StaphylococciCoagulase-Positive:Staphylococcus aureus: Can survive months outside hosts; forms yellow colonies.Coagulase-Negative:Staphylococcus epidermidis: predominant skin microbe; contributes to biofilm on medical devices.

Coagulase and InfectionsCoagulase-negative staphylococci are frequent pathogens associated with indwelling devices, forming protective biofilm.

Skin Microbiota and Immune SystemSkin microbiota protects the skin against pathogenic microbes.Beta-defensins: Antimicrobial peptides from the immune system targeting pathogens like Staphylococcus aureus.

Staphylococcal Skin InfectionsFolliculitis: Hair follicle infection.Sty: Folliculitis of eyelash.Furuncle: Abscess with pus.Carbuncle: Tissue inflammation beneath the skin.Impetigo: Crusting sores spread by self-inoculation.

Types of ImpetigoNonbullous Impetigo: Most common, usually enters through minor skin breaks.Bullous Impetigo: Caused by staphylococcal toxins.Exotoxins A & B: Cause skin exfoliation and scalded skin syndrome.

Impetigo in NewbornsPemphigus neonatorum: Newborn impetigo outbreak.Scalded Skin Syndrome: Associated with late toxic shock syndrome (TSS).

Macular Rashes and Associated SymptomsExample of a boy with cough, conjunctivitis, and macular rash spreading from face.

Streptococci EnzymesStreptolysins: Enzymes toxic to red blood cells and neutrophils; M protein inhibits complement activation.

Ersipelas InfectionCaused by Streptococcus pyogenes; results in reddish patches, potential for severe tissue destruction and sepsis.

Necrotizing FasciitisSevere bacterial infection destroying tissue; superantigenic M proteins contribute to immune damage.

Bacterial and Viral Diseases OverviewDifferentiation of bacterial and viral diseases is critical in diagnosis and treatment paths.

Infections by PseudomonadsPseudomonas aeruginosa: Opportunistic, causes post-burn infections; identified by blue-green pu

Buruli UlcerCaused by Mycobacterium ulcerans, treated with antimycobacterial drugs; linked to environmental exposure.

Acne as a Skin DiseaseMost prevalent skin condition in the U.S., affecting 17 million and over 85% of teenagers.

Classifications of AcneComedonal (mild), Inflammatory (moderate), Nodular cystic (severe) acne.

Comedonal AcneExcess sebum from sebaceous glands combines with dead skin cells, blocking hair follicles.Treatment: Salicylic acid, retinoids.

Inflammatory AcneResult of Propionibacterium acnes overgrowth; leads to pustules.Treatment includes preventing sebum with isotretinoin and antibiotics.

Nodular Cystic AcneCharacterized by deep inflamed lesions; treatment involves isotretinoin.

Another webinar introductionMaui Joyce Chua: Webinar on skin diseases from warts to lice.Date: November 1.

Overview of Viral Skin DiseasesViral diseases contribute significantly to health and economic burdens annually.

Papillomas OverviewMore than 50 papillomaviruses known to cause various types of warts; generally harmless skin growths.

Wart Transmission and TreatmentsTransmission occurs through contact; medical treatments include cryotherapy and electrodesiccation.

Smallpox OverviewCaused by variola virus; deadly disease once eradicated but has significant historical impact.

Basic Forms of VariolaVariola Major: High mortality rate.Variola Minor: Lower mortality rate, less severe infections.

Smallpox VaccinationVaccinations ceased in the 1970s; individuals vaccinated may retain some immunity.

Monkeypox OverviewSimilar to smallpox, concerns arise from transmission potential; monitored by WHO.

Chickenpox and ShinglesChickenpox is a mild disease, linked to initial HHV-3 infection

Chickenpox Transmission and RisksSymptoms include vesicular rash; risks involve severe outcomes if untreated, particularly in pregnant women.

Shingles ExplanationReactivation of varicella infections; localized vesicles with potential for severe pain.

Complications of ShinglesSevere pain may persist; treatments available for immunocompromised patients.

Chickenpox Vaccine InformationVaricella vaccine effectiveness may wane; new zoster vaccines for older adults recommended.

Hand-Foot-and-Mouth Disease OverviewCaused by enteroviruses; common in children, presents with rash and systemic symptoms.

Symptoms of Hand-Foot-and-Mouth DiseaseSigns include fever, sore throat, and rash; serious conditions can arise from infection.

Fungal Diseases IntroductionMycoses refer to fungal infections occurring in the body.

Cutaneous MycosesDermatophytes fungi colonize superficial skin layers and hair; limited penetration beyond epidermis.

Key Types of Cutaneous MycosesTinea: Ringworm types classified by location (e.g., jock itch, athlete's foot).

Three Genera of FungiTrichophyton: Affects hair, skin, nails.Microsporum: Involves hair and skin.Epidermophyton: Affects skin and nails.

Subcutaneous MycosesMore serious fungal infections from soil fungi, can enter through small wounds (e.g., Sporotrichosis).

Candidiasis OverviewOpportunistic infection from Candida species; common in immunocompromised.

Risk Factors and Treatments for CandidiasisRisk factors include obesity and diabetes; systemic candidiasis treated with antifungal medications.

Parasitic Infestation of the SkinOverview of scabies and lice; associated with intense itching and potential severe complications.

Scabies DetailsInfestation by mites causing intense itching; complications include secondary infections.

Scabies Transmission and PreventionSpread through close contact; prevention involves hygiene and cleaning of bedding.

Pediculosis (Lice) OverviewInfestation by lice, commonly linked with poor sanitation but seen in various demographics.

Transmission and Symptoms of PediculosisTransmitted via head-to-head contact; symptoms include severe itching and potential secondary infections.

Introduction to Eye Diseases WebinarDenalyn Alonzo: Speaker on microbial diseases of the eyeDate and Time: November 15, 2024

Conjunctivitis OverviewSymptoms include blurred vision, light sensitivity, swelling, itching.Common causes include bacteria (like Haemophilus influenzae) and viruses;Prevention strategies focus on proper lens care.

Ophthalmia NeonatorumSevere conjunctivitis from Neisseria gonorrhoeae; high risk of blindness if untreated.

Inclusion Conjunctivitis OverviewCaused by Chlamydia trachomatis; often linked to contaminated pools.

Trachoma OverviewMajor cause of infectious blindness; prevention involves hygiene and sanitation measures.

Consequences of Repeated Trachoma Infections Infections may cause inflammation and lead to extreme complications including blindness.

Other Infectious Eye DiseasesCommon symptoms include eye pain, redness, and blurred vision; Herpetic Keratitis is caused by HSV-1.

Acanthamoeba KeratitisRare but severe parasite infection; transmission often linked to contaminated contact lens solutions. Prevention StrategiesEffective measures include proper contact lens hygiene, regular eye examinations, and prompt treatment of any eye infections.

Acanthamoeba Keratitis TreatmentEffective treatment available if caught early; severe cases may require corneal transplants.