Skin Disorders Flashcards
Which of the following statements about rosacea are TRUE?
A) Alcohol is not a trigger
B) Topical corticosteroids are useful to treat the redness and inflammation
C) Tetracycline should be avoided because it causes photosensitivity reactions D) Topical metronidazole should be continued for 12 weeks
E) Sunlight can be helpful as a treatment
D. Alcohol is a trigger that can worsen rosacea, as is sunlight, heat, hot beverages, spicy foods, stress and the application of corticosteroids to the face (Table 2, page 1176, CTC, 7th edn). Tetracycline is one of the agents used to treat severe and persistent rosacea, though the side effect of photosensitivity does mean that the user must protect the skin during sun exposure. While topical metronidazole is the first-line treatment against mild to moderate rosacea, it can take 12 weeks of therapy to show pronounced improvement.
While tetracycline is an effective treatment for rosacea, it has several disadvantages. These disadvantages include:
a) High cost
b) Telangiectasia results from its use
c) Topical metronidazole cannot be used at the same time
d) Some food restrictions are required
e) Concurrent antacids are required to prevent GI upset
D. The absorption of tetracycline is reduced by interactions with calcium; it cannot be taken with milk or milk products. This interaction also applies to iron, zinc, aluminum, magnesium and other cations, so the intake of these items (e.g. antacids, vitamins, etc.) must be spaced by 2 hours (Table 5, page 1182, CTC, 7th edn). Tetracycline is the cheapest agent in the class of tetracyclines, and a 30-day supply costs less than $10. Telangiectasia is caused by the condition but its presence is revealed when the antibiotic clears up the symptoms. Tetracycline is frequently added to topical metronidazole therapy in recurrent and severe rosacea.
Which of the following agents would NOT be implicated in a phototoxic reaction?
a) Tretinoin
b) Doxycycline
c) Ciprofloxacin
d) Hydrochlorothiazide e) Amoxicillin
E. All of the other agents have known phototoxic side effects (Table 2, page 1194, CTC, 7th edn).
SB is a 19-year old fair-skinned woman who has sunburn after visiting a tanning salon. Any of the following would be useful to reduce erythema and/or pain EXCEPT:
a) Diclofenac 1% gel applied 6 and 10 hours after exposure
b) Calamine lotion
c) Prednisone 5mg po daily x 5 days
d) Ibuprofen 400mg q6h x 4 doses
e) Tap water compresses for 20 minutes, 4 to 6 times daily
C. Systemic corticosteroids have little effect when treating sunburn and may increase the risk of secondary infection. All of the other alternatives have been shown to provide relief. Compresses provide temporary relief. NSAIDS, either topical or oral, may decrease pain, erythema and, in some cases, edema.
Which of the following is TRUE regarding management of superficial burns?
a) Prophylactic antibiotics are first-line treatment options
b) NSAIDS should be dosed every 6 to 8 hours if needed for pain
c) Apply silver sulfadiazine cream to the area once daily
d) Avoid povidone/iodine use during pregnancy
D. Prophylactic antibiotics should be avoided in all but exceptional circumstances to avoid development of resistant infections. NSAIDS manage pain in minor burns and suppress the inflammation and should be given on a regular basis. Silver sulfadiazine should be avoided due to evidence that it may be associated with poorer healing outcomes (page 1124, CTC, 7th edn). Povidone/iodine should be avoided during pregnancy since significant iodine absorption by the baby has been reported after maternal topical use (page 1125, CTC, 7th edn).
Which of the following is FALSE regarding the treatment of pruritus?
a) Bathing is therapeutic for dry skin if water can be entrapped within the skin
b) Woolen and synthetic fabrics should be avoided
c) Systemic therapy is first line for the treatment of mild or localized itch.
d) Topical corticosteroids should not be used for long periods of time
e) Friction and irritation to the skin should be minimized
C. Topical therapy is the first choice for treatment of mild itching (page 1152, CTC 7th edn). All of the other answers are appropriate recommendations.
When treating a patient with an infected cat bite, which of the following would you prescribe?
a) Clindamycin 300mg q6h
b) Cephalexin 500mg q6h
c) Cloxacillin 500mg q6h
d) Amoxicillin/clavulanate 500mg q8h
e) Cefadroxil 1gm daily
D. Amoxicillin/clavulanate should be used due to the presence of Pasteurella multocida in cat and dog bites. This organism is resistant to clindamycin, cephalosporins (cephalexin, cefadroxil) and penicillinase-resistant penicillins (cloxacillin) {page 1110, CTC, 7th edn).
Which drug would be the safest to use for a skin infection in a patient with a recent history of anaphylaxis from a dose of intravenous penicillin G?
a) Amoxicillin
b) Dicloxacillin
c) Erythromycin
d) Cephalexin
e) Cefuroxime
C. Erythromycin, being from the macrolide class of agents, has no cross-sensitivity with penicillin G. Amoxicillin and dicloxacillin are both penicillins, so would likely provoke the same anaphylactic reaction as penicillin G. Cephalosporins (cephalexin) have some cross-reactivity with penicillins.
Staphylococcus aureus is a common etiologic agent in:
a) Urinary tract infection
b) Folliculitis
c) Acute exacerbations of chronic bronchitis
d) Pseudomembranous colitis
b. S. aureus is the most common infectious cause of folliculitis (page 1108, CTC, 7th edn). Pseudomembranous colitis is caused by E. coli. Acute bronchitis has a nonbacterial cause in >90% of cases. UTIs can be caused by a variety of organisms but S. aureus is not among them.
Which drug would be safe and effective for the treatment of cellulitis in a pregnant woman who is allergic to penicillin?
a) Minocycline
b) Levofloxacin
c) Clindamycin
d) Silver sulfadiazine
e) Cephalexin
C. Clindamycin is a reasonable agent to treat serious skin and soft tissue infections in pregnant penicillin-allergic women. The only other agent on the list that is also one of the recommended oral agents to treat cellulitis is cephalexin, and this agent has cross-reactivity with penicillins (Figure 4, page 1112, CTC, 7th edn). Fluoroquinolones have little role to play in treating common bacterial skin infections unless gram-negative organisms are suspected. Silver sulfadiazine is a topical agent used to treat burns. Minocycline is not used to treat bacterial skin infections though it has a role to play in the treatment of acne.
Red Flags by condition and drug induced conditions: Acne
INT RETINOID (ACIRETIN)
- Ethanol INC. risk of conversion to etretinate- MAJOR teratogen that remains in the body for years
- INC. Risk of MTX-liver injury
- Minipill Progestin-only contraceptives may not be effective
- Combo w/tetracyclines lead to higher risk of INC. ICP
- Caution w/concomitant use of Vitamin A doses beyond RDAs
Red Flags by condition and drug induced conditions: Acne
Acne- drug induced
Androgens, Barbiturates, Corticosteroids, Haloperidol, Lithium, Metabolic Steroids, Phenytoin, Oral Contraceptives (With levonorgestrel), bromides, iodides.
Red Flags by condition and drug induced conditions: Dermatitis
CORTICOSTEROIDS (TOPICAL)
CI: face/folds/thick psoriatic plaques
Careful with dermal atrophy, and adrenal suppression, growth rate in children
careful with secondary infxns due to immunosuppression, osteoporosis in adults
(hydrocortisone 0.5% ok around eyes as long as it’s not everyday → glaucoma, etc.)
Red Flags by condition and drug induced conditions: Psoriasis
Psoriasis
(Exogenous triggers)
● lithium
● beta blockers
● anti malarials
● NSAIDs (indomethacin)
● Ace Inhibitors
● Terbinafine
● Abrupt w/d of oral corticosteroids or high potency topical CS
● alcohol abuse
Red Flags by condition and drug induced conditions: Pressure Ulcers
DRUG INDUCED CAUSES
Corticosteroids, immunosuppressives, sedatives, analgesics
