DERM Flashcards
(89 cards)
What is the definition of urticaria (hives)?
Local or generalized superficial swelling of the skin due to an allergic reaction.
What is the first-line management for urticaria?
Non-sedating antihistamines (e.g., loratadine or cetirizine).
Sedating antihistamines (e.g., chlorphenamine) can be considered at night.
What is the management if urticaria is severe?
Oral prednisolone for severe cases.
What are the common characteristics of the rash in urticaria?
- Pruritic (itchy)
-Pale pink raised lesions
What is the definition of Herpes Zoster (Shingles)?
Acute infection caused by reactivation of varicella zoster virus (VZV), which causes chickenpox and lies dormant in the dorsal root.
Clinical diagnosis is made by the rash.
What are the risk factors for Herpes Zoster?
Age, HIV, immunosuppression (e.g., long-term steroids).
What are the key features of Herpes Zoster?
- Unilateral, dermatomal rash (most common T1-L2)
- Prodromal pain (burning sensation over dermatome)
- Rash: initial erythematous macules that progress to vesicular rash
- If rash around eye/tip of nose → Herpes Zoster Ophthalmicus
How do you manage Herpes Zoster?
- Antivirals (oral aciclovir) within 72 hours
- Analgesia (NSAIDs, neuropathic agents, oral corticosteroids if severe)
- Patient is infectious until vesicles have crusted over after 1 week
- Neuralgia post-infection is common but resolves within 6 months; give neuropathic painkillers.
What is the vaccination approach for Herpes Zoster?
- Primary VZV infection vaccination for healthcare workers who are not naturally immune.
- Reactivation vaccination for all individuals aged 70+.
What is Pityriasis Versicolor?
A superficial cutaneous fungal infection caused by Malassezia furfur, leading to patches of hypopigmented, pink, or brown rash, typically on the trunk. May scale.
How do you manage Pityriasis Versicolor?
First-line treatment: topical antifungal (e.g., ketoconazole shampoo).
If not responsive, perform skin scraping and consider oral antifungal treatment.
What is Tinea?
A term used for dermatophyte fungal infections (does not include Pityriasis/Tinea Versicolor).
Known as ringworm, commonly caused by Trichophyton species.
What is Tinea Capitis?
Fungal infection of the scalp, often caused by Trichophyton tonsurans.
Presents with itchy scalp and hair loss.
Diagnosis: scalp scraping.
Management: topical antifungal shampoo or oral antifungal.
**You wear a cap on your scalp **
What is Tinea Corporis?
Fungal infection of the trunk, legs, or arms, caused by Trichophyton rubrum and Trichophyton verrucosum.
Features: well-defined annular erythematous lesions, itchy.
Treatment: oral fluconazole.
What is Tinea Pedis?
Also known as athlete’s foot, a fungal infection of the feet.
Features: itchy, peeling skin between the toes.
Management: topical antifungal cream.
What is Scabies?
A skin infection caused by the Sarcoptes scabiei mite. Characterized by an itchy rash, often accompanied by burrows, especially in the interdigital webs, wrists, and fingers.
What is the pathophysiology of Scabies?
The mites burrow under the skin, lay eggs, and cause further infection. It is highly contagious, so inquire about contact with others.
What is Crusted Scabies?
A severe form of scabies that affects immunosuppressed patients, presenting with scaly patches instead of the usual spots/burrows.
What are the clinical features of Scabies?
PC: Extreme pruritus (itchiness).
O/E: Scratch marks, erythematous raised papules, and linear burrows on fingers, interdigital webs, and flexor wrists.
What is the treatment for Scabies?
First-line: Permethrin 5% cream.
Instructions: Apply to the whole body, leave for 8-12 hours, repeat after 1 week. Itchiness may persist for up to 4 weeks.
What are important management points for Scabies?
Avoid close contact until treatment ends.
Wash everything
Treat all household members and anyone with physical contact.
What is Impetigo?
A superficial bacterial skin infection, very contagious and common in children, caused by Staphylococcus aureus or Streptococcus pyogenes. It can be primary or secondary (e.g., from eczema, bites, or scabies).
What are the clinical features of Impetigo?
O/E: Golden, crusted lesions around the mouth.
Rash: Vesicles may form, leading to bullous impetigo (if caused by Staphylococcus aureus).
What is the treatment for limited, localized Impetigo?
Hydrogen peroxide 1% cream or topical fusidic acid (antibiotic) if not resolving.