1. Macule A macule is a change in surface color, without elevation or depression and, therefore, nonpalpable, well or ill- defined, variously sized, but generally considered less than either 5 or 10mm in diameter at the widest point.

2. Patch A patch is a large macule equal to or greater than either 5 or 10mm, depending on one's definition of a macule. Patches may have some subtle surface change, such as a fine scale or wrinkling, but although the consistency of the surface is changed, the lesion itself is not palpable

3. Papule A papule is a circumscribed, solid elevation of skin with no visible fluid, varying in size from a pinhead to either less than 5 or 10mm in diameter at the widest point.

4. Nodule A nodule is morphologically similar to a papule, but is greater than either 5 or 10 mm in both width and depth, and most frequently centered in the dermis or subcutaneous fat. The depth of involvement is what differentiates a nodule from a papule.

5. Plaque A plaque has been described as a broad papule, or confluence of papules equal to or greater than 1 cm, or alternatively as an elevated, plateau-like lesion that is greater in its diameter than in its depth.

6. Vesicle A vesicle is a circumscribed, fluid-containing, epidermal elevation generally considered less than either 5 or 10 mm in diameter at the widest point. Bulla A bulla is a large vesicle described as a rounded or irregularly shaped blister containing serous or seropurulent fluid, equal to or greater than either 5 or 10 mm, depending on one's definition of a vesicle.

7. Pustule A pustule is a small elevation of the skin containing cloudy or purulent material usually consisting of necrotic inflammatory cells.

8. Cyst A cyst is an epithelial-lined cavity containing liquid, semisolid, or solid material.

9. Ulcer An ulcer is a discontinuity of the skin exhibiting complete loss of the epidermis and often portions of the dermis and even subcutaneous fat.

10. Erosion and Fissure  An erosion is a discontinuity of the skin exhibiting incomplete loss of the epidermis, a lesion that is moist, circumscribed, and usually depressed.  A fissure is a crack in the skin that is usually narrow but deep.

11. Telangiectasia A telangiectasia represents an enlargement of superficial blood vessels to the point of being visible. Scar A scar is the replacement of normal tissue by fibrous connective tissue at the side of an injury.

12. HERPESVIRUS INFECTIONS

13.  The human herpes viruses are comprised of a DNA genome surrounded by a protein capsule that is enclosed within an envelope.  The average dimension is about 200 nm. These viruses are subclassified into alpha, beta, and gamma subtypes according to their virulence in tissue culture. Human herpesviruses 1, 2 (simplex types), and 3 (varicella- zoster virus) belong to the alpha group, Epstein-Barr virus (HHV-4) to the gamma group, and cytomegalovirus (HHV-5) is a member of the beta group.

14. Diagram of the lytic (keratinocytes) and latent (neuronal) phases of HHV-1 infection. Bottom, Viral adhesion to cell-surface receptor, intranuclear propagation, assembly, release, and cell lysis in a keratinocyte.

15. Primary Herpetic Gingivostomatitis Etiology Herpes simplex virus (HSV) Over 95% of oral primary herpes due to HSV-1 Physical contact is mode of transmission

16. Clinical Presentation 88% of population experience subclinical infection or mild transient symptoms Most cases occur in those between 0.5 and 5 years of age. Incubation period of up to 2 weeks Abrupt onset in those with low or absent antibody to HSV-1 Fever, anorexia, lymphadenopathy, headache, in addition to oral ulcers

17. Clinical Presentation Coalescing, grouped, pinhead-sized vesicles that ulcerate Ulcers show a yellow, fibrinous base with an erythematous halo Both keratinized and nonkeratinized mucosa affected Gingival tissue with edema, intense erythema, pain, and tenderness Lips, perioral skin may be involved 7- to 14-day course

18. Diagnosis Usually by clinical presentation and pattern of involvement Cytology preparation to demonstrate multinucleate virus infected giant epithelial cells Biopsy results of intact macular area show intraepithelial vesicles or early virus-induced epithelial (cytopathic) changes Viral culture or polymerase chain reaction (PCR) examination of blister fluid or scraping from base of erosion

20. Differential Diagnosis Herpangina Hand-foot-and-mouth disease Varicella Herpes zoster (shingles) Erythema multiforme (typically no gingival lesions)

21. Treatment Soft diet and hydration Antipyretics (avoid aspirin) Chlorhexidine rinses Systemic antiviral agents (acyclovir, valacyclovir) if early in course or in immunocompromised patients Compounded mouth rinse

22. Prognosis Excellent in immunocompetent host Remission/latent phase in nearly all those affected who have adequate antibody titers

23. Etiology Herpes simplex virus Reactivation of latent virus

24. Clinical Presentation  Prodrome of tingling, burning, or pain at site of recurrence  Multiple, grouped, fragile vesicles that ulcerate and coalesce  Most common on vermilion border of lips or adjacent skin  Intraoral recurrences characteristically on hard palate or  attached gingiva (masticatory mucosa)  In immunocompromised patients, lesions may occur in any oral site and are more severe (herpetic geometric glossitis).

26. Diagnosis  Characteristic clinical presentation and history  Viral culture or PCR examination of blister fluid or scraping  from base of erosion  Cytologic smear  Direct immunofluorescence examination of smear

27. Differential Diagnosis  Erythema multiforme  Herpes zoster (shingles)  Herpangina  Hand-foot-and-mouth disease

28. Treatment  Acyclovir or valacyclovir early in prodrome  Supportive  Acyclovir may be used for prophylaxis for seropositive transplant  patients  Ganciclovir may be used for human immunodeficiency virus  (HIV)-positive patients, especially those co-infected with  cytomegalovirus.  For recurrent herpes labialis, see “Therapeutics” section.

29. Etiology  Primary and recurrent forms due to varicella- zoster virus (VZV)  Primary VZV (chickenpox): a childhood exanthem  Secondary (recurrent) VZV (herpes zoster / shingles) infection: most common in elderly or immunocompromised adults

30. Clinical Presentation  Varicella (chickenpox)  Fever, headache, malaise, and pharyngitis with a 2-week incubation  Skin with widespread vesicular eruption  Oral mucosa with short-lived vesicles that rupture forming shallow, defined ulcers

31. Clinical Presentation  Herpes zoster (shingles)  Unilateral, dermatomal, grouped vesicular eruption of skin and/or oral mucosa  Vesicles may coalesce prior to ulceration and crusting.  Lesions are painful.  Prodromal symptoms along affected dermatome may occur.  Pain, paresthesia, burning, tingling  Postherpetic pain may be severe.

32. Diagnosis Clinical appearance and symptoms Cytologic smear with cytopathic effect present (multinucleated giant cells) Viral culture or PCR examination of blister fluid or scraping from base of erosion Serologic evaluation of VZV antibody Biopsy with direct fluorescent examination using fluoresceinlabeled VZV antibody