[ 1 ] Microbial Diseases of the Skin and Eyes

• Epidermis - is the thin outer portion, composed of several layers of epithelial cells.
• Dermis - is the inner, relatively thick portion of skin, composed mainly of connective tissue.
• Perspiration - provides moisture and some nutrients for microbial growth.
• Sebum - ​​secreted by oil glands, is a mixture of lipids (unsaturated fatty acids), proteins, and salts that prevents skin and hair from drying out.
• MUCOUS MEMBRANES - ​​In the linings of body cavities, such as those associated with the gastrointestinal, respiratory, urinary, and genital tracts, the outer protective barrier differs from the skin.
• Exanthem - A skin rash that arises from disease conditions is called an exanthem.
• Enanthem - on mucous membranes, such as the interior of the mouth, such a rash.
• Macular rashes - VIRAL DISEASES. Usually diagnosed by clinical signs and symptoms and may be confirmed by serology or PCR.
• Measles -

  • PATHOGEN – Measles virus
  • PORTAL OF ENTRY – Respiratory tract
  • SYMPTOMS – Skin rash of reddish macules first appearing on face and spreading to trunk and extremities
  • METHOD OF TRANSMISSION – Aerosol

  TREATMENT – No treatment; pre exposure vaccine
• Rubella (German measles)

  • PATHOGEN – Rubella virus
  • PORTAL OF ENTRY – Respiratory tract
  • SYMPTOMS – Mild disease with a macular rash resembling measles, but less extensive and disappearing in 3 days or less
  • METHOD OF TRANSMISSION – Aerosol
  • TREATMENT – No treatment; pre exposure vaccine
• Roseola

  • PATHOGEN – Human herpesvirus 6, human herpesvirus 7
  • PORTAL OF ENTRY – Respiratory tract
  • SYMPTOMS – High fever followed by macular body rash
  • METHOD OF TRANSMISSION – Aerosol
  • TREATMENT – None
• Candidiasis

  • PATHOGEN – Candida albicans
  • PORTAL OF ENTRY – Skin; mucous membranes
  • SYMPTOMS – Macular Rash
  • METHOD OF TRANSMISSION – Direct contact; endogenous infection

  TREATMENT – Miconazole, clotrimazole (topically)
• Impetigo

  • PATHOGEN – Staphylococcus aureus
  • PORTAL OF ENTRY – Skin
  • SYMPTOMS – Vesicles on skin
  • METHOD OF TRANSMISSION – Direct contact; fomites
  • TREATMENT – Topical antibiotics
• Monkeypox

  • PATHOGEN – Monkeypox virus
  • PORTAL OF ENTRY – Respiratory tract
  • SYMPTOMS – Pustules, similar to smallpox
  • METHOD OF TRANSMISSION – Direct contact with or aerosols from infected small mammals
  • TREATMENT – None
• Chickenpox (varicella)

  • PATHOGEN – Varicella-zoster virus
  • PORTAL OF ENTRY – Respiratory tract
  • SYMPTOMS – Vesicles in most cases confined to face, throat, and lower back
  • METHOD OF TRANSMISSION – Aerosol
  • TREATMENT – Acyclovir for immunocompromised patients; pre exposure vaccine
• Shingles (herpes-zoster)

  • PATHOGEN – Varicella-zoster virus
  • PORTAL OF ENTRY – Endogenous* infection of peripheral nerves (*Endogenous infections are infections caused by microorganisms already part of the host microbiota.)
  • SYMPTOMS – Vesicles typically on one side of waist, face and scalp, or upper chest
  • METHOD OF TRANSMISSION – Recurrence of latent chickenpox infection
  • TREATMENT – Acyclovir; preventive vaccine
• Folliculitis

  • PATHOGEN – Staphylococcus aureus
  • PORTAL OF ENTRY – Hair follicle
  • SYMPTOMS –  Infection of hair follicle
  • METHOD OF TRANSMISSION –  Direct contact; fomites; endogenous infection*
  • TREATMENT – Draining of pus; topical antibiotics
• Acne

  • PATHOGEN – Propionibacterium acnes
  • PORTAL OF ENTRY – Sebum channels
  • SYMPTOMS – Inflammatory lesions originating with accumulations of sebum that rupture a hair follicle
  • METHOD OF TRANSMISSION – Direct contact
  • TREATMENT – Benzoyl peroxide, isotretinoin, azelaic acid
• Warts

  • PATHOGEN – Papillomavirus
  • PORTAL OF ENTRY – Skin
  • SYMPTOMS – A horny projection of the skin formed by proliferation of cells
  • METHOD OF TRANSMISSION – Direct contact

  TREATMENT – Removal by liquid nitrogen cryotherapy, electrodesiccation, acids, lasers
• Pediculosis (lice)

  • PATHOGEN – Pediculus humanus capitis
  • PORTAL OF ENTRY – Skin
  • SYMPTOMS – Itching
  • METHOD OF TRANSMISSION – Primarily direct contact; possible fomites such as bedding, combs
  • TREATMENT – Topical insecticide preparations
• Conjunctivitis  - an inflammation of the conjunctiva, often called by the common name red eye, or pinkeye.
• Ophthalmia Neonatorum - a serious form of conjunctivitis caused by Neisseria gonorrhoeae (the cause of gonorrhea).
• Inclusion Conjunctivitis - Also called Chlamydial conjunctivitis. It is caused by Chlamydia trachomatis, a bacterium that grows only as an obligate intracellular parasites.
• Trachoma - A serious eye infection, and probably the greatest single cause of blindness. It is caused by certain serotypes of Chlamydia trachomatis but not the same ones that cause genital infections.
• Herpetic Keratitis - The disease is an infection of the cornea, often resulting in deep ulcers, that may be the most common cause of infectious blindness in the United States.