Blisters and emergencies Flashcards

Question

Describe how eczema herpeticum occurs [2]

Answer 1

**Atopic dermatitis** results in **impaired skin protective function**, allowing **easier infection of HSV***Disruption of the epidermal barrier is the most important risk factor* **Inflammation and immune dysregulation** may allow for **widespread infection of the virus** HSV requires intact cellular immunity to be contained

Answer 2

The skin lesions of eczema herpeticum typically present as **painful clusters of blisters, fluid-filled elevations of the skin** **Areas of rapidly worsening, painful eczema** The blisters appear widely over the body but are **most common on the face, neck, and trunk**. **Older blisters** that have **burst** and **dried** commonly form **“punched out” erosions**, which are **circular breaks in the continuity** of the skin that may **bleed or produce pus.** Possible **fever, lethargy, lymphadenopathy or distress**

Answer 3

presentation of EH that is easily **mistaken for impetigo** and most often seen in patients with severe AD and recurrent EH

Answer 4

Rarely, HSV may spread to the eye resulting in **herpes keratitis** **Ganciclovir ointment five times daily** (3 hourly) for 7-10 days

Answer 5

Acyclovir Flucoxacillin

Answer 6

**Erythema multiforme (EM) is a skin hypersensitivity reaction that commonly occurs secondary to an infection or drugs.*** A hypersensitivity reaction is an exaggerated immune reaction that occurs in response to an antigen or allergen.*

Answer 7

**Causes**: **Drugs** or Infections (**HSV, Mycoplasma**) **EM Minor** – target lesions + mild/ no mucosal involvement **EM Major** – target lesions + 1 or more mucosal surfaces involved

Answer 8

**Symmetrical** **distribution** on the **extensor surfaces of acral extremities** **Mucosal lesions** commonly involve the **oral** **mucosa** and can lead to **erythema, erosions, and/or bullae.**

Answer 9

EM is characterised by the presence of target lesions that are usually < 3 cm in size. These lesions have three striking features: * **A central blister or dusky red area** * **A surrounding pale ring of oedema** * **An erythematous halo in the periphery** It does not usually affect the mucous membranes but can cause a sore mouth (**stomatitis**).

Answer 10

Type 1 Type 2 Type 3 **Type 4** EM is considered a cell-mediated (type IV) hypersensitivity reaction, which is an abnormal cell-mediated reaction initiated by T cells. The exact mechanism leading to EM is incompletely understood, but it appears to be an abnormal immune reaction to a drug metabolite or viral antigen that becomes expressed by keratinocytes within the skin

Answer 11

Where there is no clear underlying cause it may be worth investigating further, for example doing a **chest xray to look for mycoplasma pneumonia.**

Answer 12

Management * EM typically develops over 3-5 days and improves over 2 weeks. Some patients may get persistent or recurrent episodes. * Stop the drug * Treat the underlying infection * Treat with a week of **oral** **prednisolone** if severe mucosal pain/ difficulty eating

Answer 13

**Stevens-Johnson syndrome** is a severe systemic reaction affecting the **skin and mucosa** that is almost always caused by a **drug reaction**. **Presentation**: * **Patients** usually start with non-specific symptoms of **fever, cough, sore throat, sore mouth, sore eyes and itchy skin**. * They then develop a **purple or red rash** that **spreads across the skin and starts to blister**. * **Nikolsky sign is positive** in erythematous areas - blisters and erosions appear when the skin is rubbed gently ## Footnote **NB**: Nikolsky sign = where very gentle rubbing of the skin causes it to peel away

Answer 14

**SPANLOC** * **S**ulphonamide * **P**enicillin * **P**henytoin * **Al**lopurinol * **N**SAIDS * **L**amotrigine * **O**CP * **C**arbamazepine Most commonly caused by drugs. Less commonly infection eg **Mycoplasma**

Answer 15

SJS < 10% body surface area TEN > 30% body surface area

Answer 16

* Erythematous or purpuric macules * Diffuse erythema * Targetoid/ atypical target lesions * Flaccid blisters

Answer 17

**Dx**: - **skin biopsy** Severity: - **SCORTEN** ## Footnote sum of five points or more indicates a mortality risk of over 90%

Answer 18

**staphylococcus** **aureus** bacteria that produces **epidermolytic** toxins. These toxins are **protease enzymes** that break down the **proteins that hold skin cells together** When a skin infection occurs and these toxins are produced, the skin is damaged and breaks down. This condition usually affects children under 5 years. Older children and adults have usually developed immunity to the epidermolytic toxins.

Answer 19

**Fever**: - High fever (>38.9°C) **Rash**: - A **diffuse**, **blanching** **erythroderma** resembling **sunburn** usually appears early in the disease course. - **Desquamation**, particularly on the **palms and soles**, typically occurs **one to two weeks after the onset of illness** **Myalgias and arthralgias** are frequently reported; **Hypotension**: - Hypotension or shock may be present, often manifesting as systolic blood pressure less than 90 mmHg.

Answer 20

* Admit * Fluids * **IV flucloxacillin** and **clindamycin** *Clindamycin suppresses toxin production, while flucloxacillin targets the bacterial cell wall.* * If methicillin-resistant Staphylococcus aureus (MRSA) is suspected, **vancomycin** or **daptomycin** can replace flucloxacillin.

Answer 21

**Type 1** – Polymicrobial (anaerobes + aerobes) **Type 2** – Group A beta-haemolytic streptococci **Type 3** – Clostridium perfringens; also associated with Vibrio species infection from seafood ingestion or water contamination of wounds. **Type 4** - Fungal infection

Answer 22

**Lichen planus**

Answer 23

Lichen planus

Answer 24

**Co-amoxiclav**