DISEASES OF THE SKIN AND EYES;WOUNDS AND BITES CHAPTER 19 Copyright © 2012 John Wiley & Sons, Inc. All rights reserved.

Anatomy Review - Skin Epidermis Cellular Thick Waterproof Dead surface Copyright © 2012 John Wiley & Sons, Inc. All rights reserved.

Mucous Membranes Epithelium Mucus Protective features Lysozyme Chemicals Antibodies Copyright © 2012 John Wiley & Sons, Inc. All rights reserved.

Eyes Conjunctiva Cornea Glands Protective features Lashes Blinking reflex Tear flow Molecules IgA Lysozyme Copyright © 2012 John Wiley & Sons, Inc. All rights reserved.

Additional Defenses Microflora Salt tolerance Skin cell shedding Copyright © 2012 John Wiley & Sons, Inc. All rights reserved.

Bacterial Skin Diseases – Staphylococcus aureus Folliculitis (Pimples) Invasion of hair follicles Eyelash infection - Sty Multiple follicles – Carbuncle Many carriers Low bacterial counts needed to infect wounds Scalded skin syndrome Exfoliative exotoxins Infants most affected Outer skin layers shed High fever Septicemia and shock may occur Copyright © 2012 John Wiley & Sons, Inc. All rights reserved.

Staphylococcal Impetigo Impetigo of Newborn Crusting vesicles on skin surface Antimicrobial lotions needed Carriers need to be careful in hospitals and at home Copyright © 2012 John Wiley & Sons, Inc. All rights reserved.

Bacterial Skin Diseases – Streptococcus pyogenes Scarlet Fever Bacteriophage toxin causes rash Strep. throat often also seen Complications – glomerulonephritis and rheumatic fever Treatment should not be delayed Many carriers Copyright © 2012 John Wiley & Sons, Inc. All rights reserved.

Streptococcus pyogenes Erysipelas St. Anthony’s fire Historically high mortality, not so now Red raised rubbery lesion Focal spread may occur Septicemia Pneumonia Endocarditis Abscesses Copyright © 2012 John Wiley & Sons, Inc. All rights reserved.

Pyoderma/Impetigo Microbes involved Strep./Staph. Corynebacterium Childhood infection Skin depigmentation may occur Penicillin treats most infections Acne Propionibacterium acnes Adolescent condition Careful skin washing Antibiotics, Acutane Copyright © 2012 John Wiley & Sons, Inc. All rights reserved.

Burn Infections Pseudomonas aeruginosa Common in pools and improperly chlorinated hot tubs Dermatitis Ear infections Severe respiratory infections in burn victims Serratia Providencia Treatments Debridement Skin cell replacement Copyright © 2012 John Wiley & Sons, Inc. All rights reserved.

Viral Skin Diseases - Rubella German Measles The disease Systemic with skin rash, joint pain Mild but can cause birth defects Stillbirth Deafness, heart and liver problems Respiratory transmission Immunity and Prevention MMR vaccine, all preadolescent girls Copyright © 2012 John Wiley & Sons, Inc. All rights reserved.

Viral Skin Diseases - Rubeola Measles The disease Lymphatic tissue affected Rash and fever develop, cough and conjunctivitis Middle ear infections and URT infections may occur Incidence and transmission Respiratory route of transmission Immunity and Prevention MMR vaccine, target for global eradication Copyright © 2012 John Wiley & Sons, Inc. All rights reserved.

Vaccination Success Copyright © 2012 John Wiley & Sons, Inc. All rights reserved.

Herpesviridae Skin Diseases Roseola HHV-6, fever and rash Self-limiting but latent Shed in saliva of most adults Chickenpox/ Shingles Varicella zoster virus (VZV) Respiratory route of infection Systemic symptoms accompanied by vesicular rash May be fatal in adults, childhood vaccination provides 20 years immunity Latent virus, shingles vaccine is newly available Copyright © 2012 John Wiley & Sons, Inc. All rights reserved.

Other Pox Diseases Smallpox Eradicated Virus reserves exist ? Bioterrorism Cowpox Milder disease Similar lesions Led to vaccine for smallpox Monkeypox Similar to smallpox virus ? Species barrier? Vaccination precaution in endemic areas Copyright © 2012 John Wiley & Sons, Inc. All rights reserved.

Warts Human Papilloma virus (HPV) Affect skin and mucus membranes (Dermal. STD) May require excision, freezing Link between some strains and cervical cancer Gardasil vaccine Now recommended for young girls and boys Copyright © 2012 John Wiley & Sons, Inc. All rights reserved.

Fungal Skin Disease - Dermatomycoses Ringworm Tinea cruris (groin) Tinea capitis/barbae (head/ beard) Tinea pedis/ unguium (foot/ toenails) Very contagious Secondary bacterial infections may occur OTC medications available Triazoles Copyright © 2012 John Wiley & Sons, Inc. All rights reserved.

Subcutaneous Fungal Disease Sporotrichosis Sporothrix schenkii Gardeners, farmers Transmitted from animals or humans Ulceration and inflammation at puncture site KI treats subcutaneous lesions Copyright © 2012 John Wiley & Sons, Inc. All rights reserved.

Opportunistic Mycoses Candidiasis (Candida albicans) Oral or vaginal infections common May cause systemic infections in immunocompromised (AIDS) Aspergillus may also cause skin and respiratory disease Copyright © 2012 John Wiley & Sons, Inc. All rights reserved.

Bacterial Eye Diseases Opthalmia neonatorum Neisseria gonorrheae Transmission via birth canal Routine antibiotics or silver nitrate Reduced incidence of blindness Copyright © 2012 John Wiley & Sons, Inc. All rights reserved.

Trachoma Chlamydia trachomatis Leading cause of preventable blindness worldwide 500 million affected S.W. Native Americans only at risk group in U.S.A. Flies are a vector Copyright © 2012 John Wiley & Sons, Inc. All rights reserved.

Viral Eye Diseases Epidemic Keratoconjunctivitis Adenovirus (Shipyard Eye) Virus carried in dust Cornea may be cloudy for up to 2 years Sometimes nosocomial HSV Keratoconjunctivitis Complication for cold sore sufferers Leading cause of non-retinal blindness in U.S.A. Copyright © 2012 John Wiley & Sons, Inc. All rights reserved.