Chapter 7: Viral infections Flashcards
Herpes simplex
-‐ Herpetic whitlow (herpetic paronychia): affects fingers. Herpes barbae: in area injured during shaving. Herpes gladiatorum (scrumpox): in wrestlers and rugby players
-‐ Eczema herpeticum (Kaposi’s varicelliform eruption): diffuse, life-‐threatening HSV infection in pts with pemphigus, Darier’s, and eczema
-‐ Balooning degeneration: nuclear clearing and enlargement seen in viral infections
-‐ Tzanck cell: acantholytic epithelia cell (free-‐floating)
-‐ Avoid topical benzocaine in children (assoc w/ methemoglobinemia)
Varicella
-‐ Latency in dorsal spinal ganglia
-‐ Skin: vesicle surrounded by erythema (dewdrop on a rose petal).
-‐ Oral: vermillion border of lips and palate. White vesicles, which rupture.
-‐ Gingival involvement may resemble 1ary herpes, but is relatively painless
-‐ Most common complication in children: skin infections. Adults: pneumonitis
Herpes zoster
-‐ Phases: prodrome, acute (vesicles) and chronic (post-‐herpetic neuralgia)
-‐ 66% of cases affects thoracic dermatome
-‐ Zoster sine herpete (zoster without rash): recurrence in the absence of vesicles
-‐ Oral: similar to varicella (white opaque vesicles that rupture)
-‐ Bone necrosis with loss of teeth can occur (secondary to damage to blood vessels)
-‐ Tip of the nose involvement: sign that nasocilliary branch of trigeminal nerve is involved
-‐ Herpes zoster ophthalmicus: can result in blinding
-‐ Ramsay-‐Hunt syndrome: zoster of ear, facial paralysis, hearing loss, and vertigo
-‐ Post-‐herpetic neuralgia: in 15% of patients; pain lasting 1-‐6 months after rash
Mononucleosis
-‐ Fever, prominent cervical lymphadenopathy, oropharyngeal tonsillar enlargement and soft palatal petechiae. Also NUG-‐like lesions.
-‐ Chronic fatigue syndrome: tiredness and fatigue in patients with mononucleosis (EBV?)
-‐ Histo: ~ lymphoma. RS-‐like cells (CD15 –ve) near necrotic areas. EBV+
-‐ Dx: Paul-‐Bunnel heterophil Ab: Ig that agglutinate sheep erithrocytes
-‐ Tx symptomatic. Avoid antibiotics (can cause allergic morbiliform skin rashes)
Cytomegalovirus
-‐ May cause acute sialadenitis: xerostomia, swelling and pain
-‐ Oral CMV: chronic ulcerations (often there is co-‐infection with HSV)
-‐ Histo: owl eye cell (PAS and GMS +) in vascular endothelium and salivary ductal epithelium
-‐ Tx: ganciclovir (foscarnet 2nd line)
Enteroviruses
-‐ Herpangina: 2-‐6 lesions (vesicles then ulcers) in posterior soft palate
-‐ HFM: 1-‐30 lesions (vesicles then ulcers), not confined to posterior mouth
-‐ ALP: 1-‐5 nodules (lymphoid aggregates), no vesiculation or ulceration
Measles (rubeola)
-‐ Aka 9 day measles: caused by paramyxovirus, Morbillivirus
-‐ 3 C’s: coryza, cough, conjunctivitis (1st stage), rash (2nd stage), rash and fever subside (3rd stage)
-‐ Koplik’s spots: erythema with small blue/white macules (“grains of salt” on red background).
Due to foci of epithelial necrosis. Seen in 1st stage.
-‐ Other oral: candidiasis, NUG and necrotizing stomatitis (if malnutrition is present)
-‐ Subacute sclerosing panencephalitis: personality changes, seizures, coma and death
-‐ Histo: syncitial giant cells and Warthin-‐Finkeldey giant cells (multinucleated giant lymphocytes)
Rubella (german measles)
-‐ Aka 3-‐day measles: caused by Togavirus (rubivirus)
-‐ Congenital rubella syndrome: deafness, heart disease, and cataracts
-‐ Forchheimer’s sign: small dark red papule on the soft palate, extending into hard palate
Mumps
-‐ Caused by paramyxovirus (rubulavirus). SG enlargement (75% bilateral, usually parotid)
-‐ Epididymoorchitis: Second most common finding. Testicle involvement in 25% pts
-‐ Oral: swelling/redness of Wharton’s and Stensen’s duct, enlargement of FOM
HIV/AIDS
-‐ Acute self-‐limited viral syndrome: 1-‐6 wks after HIV contact, similar to mononucleosis
-‐ HIV infects CD4+ T-‐helper cell. Normal CD4/CD8 ration: 0.9 – 1.9 (in HIV -‐> more CD8 over time)
-‐ Initial infection asymptomatic or acute response (50-‐70% of pts, after 1-‐6 weeks, ~ mononucleosis, lasts a few weeks and is followed by asymptomatic period)
-‐ AIDS-‐related complex (ARC): chronic fever, weight loss, diarrhea, oral candidiasis, zoster and/or OHL (after acute response, but before overt AIDS)
-‐ Overt AIDS: ARC + opportunistic infections (50% pneumonia; also CMV, HSV, fungus, toxo)
-‐ Best marker for transition from HIV to AIDS is viremia
-‐ AIDS-‐dementia complex: CNS involvement (progressive encephalopathy)
-‐ Oral manifestations strongly assoc w/ HIV: candidasis, hairy leukoplakia, Kaposi, NHL and periodontal disease (NUG, NUP, linear gingival erythema, pain a characteristic sign)
-‐ OHL: balloon cells and “nuclear beading” (peripheral margination of chromatin)
-‐ Persistent generalized lymphadenopathy: Present > 3 mths and involving 2+ extra-‐inguinal sites
-‐ CMV is the most common opportunistic viral pathogen in AIDS
-‐ NHL: 2nd most common malignancy in AIDS. 60x greater chance. CNS most common site.
-‐ Oral TB: ulcer, granular leukoplakia or exophytic mass (PPD often –ive)
-‐ Hyperpigmentation of skin, nails and mucosa also seen (meds, adrenal gd destruct, idiopathic)
-‐ HIV-‐related SG disease: parotid enlargement (60% bilateral) + lymphadenopathy. Looks like BLEL. Multiple epithelium-‐lined cystic spaces with reactive lymphoid stroma. The p-‐24 core Ag of HIV can be shown in dendritic cells.
-‐ Diffuse infiltrative lymphocytosis syndrome (DILS): increased NHL risk. Due to CD8 infiltration.
CD8+. Followed by lymphoepithelial cyst formation. Can affect lung. Tx: prednisone
-‐ Thrombocytopenia: related to decreased survival
-‐ HSV: same prevalence, but widespread, atypical and longer duration
-‐ HIV+ have unusual variants of HPV: 7 (Butcher’s wart) and 32 (Heck’s)
-‐ Histoplasmosis is the most common fungal infection in HIV+
-‐ HIV+ have more herpetiform and major apthtous ulcers
