Infections Flashcards
(51 cards)
1
Q
What is the most common bacterial infection?
A
Impetigo
2
Q
What are the causative agents of impetigo?
A
- Bullous – MC caused by Staphylococcus Aureus
2. Non-Bullous – MC caused by Steptococcus
3
Q
When does impetigo occur?
A
- Seen following minor skin injury (bug bite, eczema)
- Children - have higher rates of infection
- Risk factors - warm moist climates, poor hygiene
4
Q
How is impetigo dx?
A
Dx – clinically or by bacterial culture
5
Q
What complications may be asst. with impetigo?
A
- Px – If left untreated may last for wks – mo’s
- Poststrep. glomerulonephritis may follow in kids 2-4yo
- Rheumatic fever - not been reported as a complication
6
Q
What are the sxs of impetigo?
A
- Varied sizes
- Localized or Widespread
- At site of skin injury
- +/- Bullae, papules, vesicles coalescing
- Honey-Colored Crusting
- Satellite lesions
7
Q
What is the tx for limited and localized impetigo?
A
- Topical therapy best
2. 2% Mupirocin oint/crm (Bactroban) TID for 10days
8
Q
What is the tx for widespread and severe impetigo?
A
Oral antibiotics (penicillinase-resistant antibx’s)
Dicloxicillin 250mg QID for 5-10days
Cephalexin (Keflex) 250mg QID for 5-10days
9
Q
What is the tx for recurrent impetigo?
A
- 2% Mupirocin oint BID for 5days, repeated monthly for several mo’s
- Erradicates nasal carriers of Staph A.
10
Q
Define cellulitis
A
Infection of the dermis and subcutis
Typically develops near sites of skin injury
Surg wounds, bites, burns, abrasions, lacerations, dermatosis
11
Q
What are the causative agents of cellulitis?
A
Streptococcus and Staph A.
12
Q
Wha are the risk factors for cellulitis?
A
DM, Liver dis., Imm compr, Poor Lymph/Circ
13
Q
How is cellulitis diagnosed?
A
Made clinically, Bact Cx difficult
Labs - CBC wbc’s and ESR elevated
14
Q
What is the prognosis for cellulitis?
A
- Recurrance common in sites of poor circ.
2. Severe forms can progress to Necrotizing Faciitis
15
Q
What are the sxs of cellulitis?
A
- Sx’s of localized pain and tenderness before rash
- MC location is lower extr
A. Can be seen on any part of body - Expanding, Eryth, Warm, Tender to Painful, plaque with indefinite borders
- +/- vesicles, hemorrhage, necrosis, or abcess’s seen
16
Q
What are the treatment options for acute episodes of cellulitis?
A
- Systemic Antibx (penicllinase resistant penicillin)
- Dicloxicillin 500-1000mg PO QID for 7-14days
- Cephalexin (Keflex) 500mg QID for 7-14days
- Augmentin 875mg BID for 7-14days
- Penacillin allergic?
Erythromycin 250-500mg QID for 7-14days
Zithromax (Z-pak) 500mg on day 1, 250mg days 2 to 5
Clarithromycin (Biaxin) 250-500mg BID for 7-14days
17
Q
Define erysipelas
A
Acute, inflammatory form of cellulitis
History of prodromal Sx’s up to 48hrs prior
18
Q
How is erysipelas different from cellulitis?
A
- Differs from cellulitis in that…
lymphatic involvement (“streaking”) is prominent - More superficial and with clearer margins
- MC caused by Streptococci (grp A)
19
Q
What are the risk factors for erysipelas?
A
Lymphatic and Venous Circ. impairment
20
Q
How is erysipelas diagnosed?
A
Made clinically, Bact Cx difficult
Labs - CBC wbc’s and ESR elevated
21
Q
What is the prognosis for erysipelas?
A
Recurrence common in sites of poor circ.
22
Q
What are the sxs of erisipelas?
A
- Sx’s of itch, burn, pain
- MC location is lower extr
Also seen on face/ears/buttocks - Tense, Eryth, Warm, Tender, elevated patch with irreg outline but well demarcated border
- +/- Red streaks of lympangitis
23
Q
How is acute erysipelas treated?
A
- Systemic Antibx (penicllinase resistant penicillin)
- Dicloxicillin 500-1000mg PO QID for 7-14days
- Cephalexin (Keflex) 500mg QID for 7-14days
- Augmentin 875mg BID for 7-14days
- Penacillin allergic?
A. Erythromycin 250-500mg QID for 7-14days
B. Zithromax (Z-pak) 500mg on day 1, 250mg days 2 to 5
C. Clarithromycin (Biaxin) 250-500mg BID for 7-14days
24
Q
How are severe erysipelas cases treated?
A
Severe infections may require Hosp and IV antibx
Recurrent episodes
Prolonged antibx prophylaxis
25
What are furuncles and carbuncles?
1. Walled off, deep, painful, firm or fluctuant mass
2. Enclosing a collection of pus = Boils, Abcess’s
3. Often evolves from a superficial folliculitis
4. Carbuncles = interconnected and infected, abcessed, follicles
5. MC caused by Staph A.
6. Uncommon in children
26
What are the risk factors for furuncles and carbuncles?
– Occluded and Sweaty areas, Obesity, Poor Hygiene, DM
27
What is the prognosis fr furuncles and carbuncles?
Either comes to a head and ruptures or is reabsorbed
| Recurrent Furunculosis can be difficult to eradicate
28
What are the sxs for furuncles?
Eryth, Edema, Warm, Painful
Initially - firm Nodule
Later - fluctuant Abcess
29
What are the sxs of carbuncles?
Same inflammation seen
Becomes confluent w/in several days
Carbuncles MC seen on post neck
+/- Malaise, chills, fever
30
How are furuncles treated?
1. Warm, moist compresses 15-30min several x a day for firm/small
2. I&D +/- iodoform packing for fluctuant/larger lesions
3. May use systemic antibx if think secondary cellulitis involved
A. Dicloxicillin 500-1000mg PO QID for 7-14days
B. Cephalexin (Keflex) 500mg QID for 7-14days
C. Penacillin allergic?
D. Erythromycin 250-500mg QID for 7-14days
31
How are carbuncles txed?
Require Systemic Antibx (as above) and Surgical Management
32
How is recurrent furunclosis treated?
1. Topical eradication of nasal Staph A. (2% Mupirocin oint)
2. Environmental changes and antibacterial washes (hibaclens, betadine)
3. Address underlying risk factors (obesity, DM, tight clothes, hygiene)
4. Systemic Antibx if topical tx fails
A. Dicloxicillin with Rifampin 600mg QD for 7-10days
33
What is erythrasma
Chr bacterial infection affecting intertriginous areas
Corynebacterium minutissimum (gram + rod)
From Greek for “red spot”
Mimics dermatophyte infections
MC seen in adults
34
What are the rf for erythrasma?
Humid climates, Occlusive clothing, Obesity, DM
35
How is erythrasma dx?
Bact Cx, Neg KOH, Woods Lamp (coral red)
36
What are the ddx for erythrasma?
Fungal, Candidal, Seb Derm, Inverse Psor
37
What are the sxs of erythrasma?
Located to intertriginous areas
Asymptomatic, occasional sx’s
Duration of Mo’s to Yr’s
Sharply defined red-brown (brawny) patch without scale if site occluded, often symmetrical or in several web spaces
38
How is erythrasma treated?
1. Prevention
A. Keep area clean – wash with Panoxyl (BPO) 5% bar in shower
B. Keep area dry – Loose fitting clothing, Zeasorb AF powder
2. Topical
A. BPO gel BID x 7days or until clear
B. E-mycin 2% BID x 7days or until clear
C. Clindamycin 2% BID x 7days or until clear
3. Systemic
A. E-mycin 250mg QID for 14days
B. Tetracyclin 250mg QID for 14days
39
What is tinea corporus
Ringworm of the body
Round Annular Lesions (central clearing and scaly border)
Deep Inflammatory Lesions
Seem in all age groups
40
What are rf for tinea?
MC spread from fungus of feet, Animal workers
41
What are the sxs of tinea corporis?
#1 Sx = Itching
Variable sized well demarcated erythematous plaques with peripheral enlargement and central clearing
+/- Pustules/Vesicles
Intensely inflammed lesions with elevated and boggy pustular surfaces
42
How is tinea corporis treated?
1. Prevention
A. Treat underlying Tinea infections
2. Topical
A. Lamisil, Mentax, Naftin – Allylamines
B. Clotramin, Spectazole, Oxistat – Imidazoles
C. AAA BID for 2-4wks or until clear (+1wk)
3. Systemic
A. See chart
B. Short course of prednisone for highly infl lesions
43
What is tinea pedis?
The MC area affected by dermatophytes = FEET
Tinea Pedis = “Athlete’s foot” MC caused by T. rubrum
MC in young-mid aged adults (Men>Women)
44
What are the rf for tinea pedis?
= Occlusive/Prolonged shoe wear, Hyperhidrosis
45
What are the morphological types of tinea pedis?
1. Interdigital Tinea Pedis (MC 4th and 5th Web spaces)
2. Chronic Scaly Infection of Plantar Surface
3. Acute Vesicular Tinea Pedis
4. Ulcerative
46
What are the sxs of tinea pedis?
1. #1 Sx = Itching
2. Dry scaly or Wet and macerated web spaces
3. Plantar hyperkeratosis with fine silvery white scale (+/- hands inf too)
4. Inflammatory infection with vesicles/bullae, (+/- thick scale trapped)
5. Ulcers and Erosions in web spaces, commonly bacterial secondary infection
47
What is the tx for tinea pedis?
```
1. Prevention
A. Allow feet to air out as much as possible
B. Wear wider shoes
C. Dr Scholl’s Lamb wool to web spaces
D. Zeasorb AF powder
2. Topical
A. Lamisil, Mentax, Naftin – Allylamines
B. Clotramin, Spectazole, Oxistat – Imidazoles
C. AAA BID for 2-4wks or until clear
3. Systemic
See chart
```
48
What is tinea cruris?
Subacute or Chr dermatophyte infection of crural folds
Tinea Cruris = “Jock Itch”
MC caused by T. rubrum or metngrophytes
MC in adults (Men>Women)
49
What are the sxs of tinea cruris?
Often prior Hx of Tinea Pedis/Ungium, Pruritis
50
Where is tinea cruris found?
1. Seen on groin, thighs, buttocks (scrotum and penis spared)
2. Large well demarcated dull red/tan/brown patchs or plaques
3. +/- Papules/Pustules at margins and central clearing
51
How is tinea cruris treated?
1. Prevention
A. Keep area clean – wash with Panoxyl (BPO) 5% bar in shower
B. Keep area dry – Loose fitting clothing, Zeasorb AF powder
C. Treat any underlying Tinea Pedis/Ungium
2. Topical
A. Lamisil, Mentax, Naftin – Allylamines
B. Clotramin, Spectazole, C. Miconazole – Imidazoles
AAA BID for 2-4wks or until clear
Systemic
See chart
