dermato lecture

Question 1

Yellow crusted erosions around perioral and perinasal regions

Answer 1

impetigo

Question 2

impetigo

Answer 2

Painful sores around mouth and nose for past 5 days Associated with fever and lethargy • Yellow crusted erosions around perioral and perinasal regions
Staphylococcus aureus, group A beta-haemolytic streptococcus • Portals of entry
– Adjacent to sites of S. aureus colonisation e.g. nares
–Secondary infection
• Minor breaks in epidermis • Preexisting dermatoses • Other infections e.g. eczema herpeticum • Wounds
Superficial: asymptomatic • Ecthyma: painful, tender • Erosions with crusts, 1-3 cm, central healing in weeks
–Scattered/discrete
– Confluent
– Satellite lesion • Bullous impetigo (intertriginous) • Ecthyma: ulceration with thick, adherent crust; indurated

Question 3

treatment of impetigo

Answer 3

Prevention: Reduced colonisation • Topical antibiotics: Mupirocin, retapamulin • Systemic antibiotics: sensitivity of isolated organisms

Question 4

cellulitis

Answer 4

Acute, spreading infection • Dermal and subcutaneous tissues • Red, hot, tender area of skin
Portal of infection
– Break in skin/mucosa
– Tinea pedis, leg and foot ulcers
– Cutaneous seeding: bacteraemia/sepsis • Risk factors
– Host defense defects
– Diabetes mellitus
– Drug and alcohol abuse
– Cancer and chemotherapy
– Chronic lymphoedema: post mastectomy, previous cellulitis/erysipelas
Infection spreads to tissue spaces and cleavage planes
– Hyaluronidases break down polysaccharide ground substances
– Fibrinolysis digest fibrin barriers
– Lecithinases destroy cell membranes • Local tissue devitalisation anaerobic infection • Reaction to cytokines and bacterial superantigens

Question 5

clinical manifestation of cellulitis

Answer 5

Clinical manifestations
– Fever, chills
– Local pain and tenderness
– Necrotizing infections: more local pain & systemic symptoms
– Red, hot, oedematous, shiny plaque (at portal of entry)
– Borders: sharply defined, irregular, slightly elevated
– Vesicles/bullae/erosions/abscesses/haemorrhage/necrosis
– Lymphangitis
– Tender, enlarged regional lymph npdes

Question 6

treatment of cellulitis

Answer 6

Treatment: systemic high dose antibiotics
– Type and sensitivity
-unasyn or cloxacilin in ummc

Question 7

scarlet fever

Answer 7

Aetiology
– Group A beta-haemolytic streptococcus (S. pyogenes),
erythrogenic toxin-producing strains – Exfoliative toxin (ET)-producing S.aureus
• Infection
– Pharyngitis
– Tonsillitis
– Infected wound
– Infected dermatoses

Question 8

SCARLET FEVER

Answer 8

White strawberry tongue (white with scattered
red, swollen papillae) red strawberry tongue
(4th/5th day: hyperkeratotic membrane sloughed,
lingular mucosa bright red)