Eczema (dermatitis) Flashcards
Part of common rashes > Seborrhoeic dermatitis, Contact dermatitis , Atopic Dermatitis (Eczema)
1
Q
What is eczema/dermatitis?
A
Itchy skin lesions
2
Q
What is spongiosis?
A
Oedema between keratinocytes
(most common type of cells in the epidermis - produces keratin)
= leading to fluid accumulation, sometimes forming vesicles
3
Q
Which area of the body is commonly affected in eczema?
A
Flexor surfaces
= eg, inside elbows, behind knees
4
Q
What are the key features of acute eczema?
A
(1) Papulovesicular, erythematous lesions
= red and has both characteristics of a papule (a small, raised bump) and a vesicle (a small blister filled with fluid)
(2) Itchy
(3) Ill-defined
(4) Oedema between cells (spongiosis)
(5) May coalesce into vesicles/bullae (eg, dyshidrotic eczema)
(6) Oozing, scaling, crusting
5
Q
What are the histological features of acute eczema?
A
- Inflammatory infiltrate (lymphocytes) in upper dermis
- Fluid collections around keratinocytes (spongiosis)
- When fluid builds up, it forms a tiny blister/vesicle
6
Q
What are the key features of chronic eczema?
A
- Thickening (lichenification)
- Elevated plaques
- Increased scaling
- Excoriation (due to scratching)
- Secondary infection
(Staph. aureus, HSV)
7
Q
What infection is suggested by crusting in atopic eczema?
A
Staphylococcus aureus infection
8
Q
What is eczema herpeticum?
A
A severe complication of atopic eczema caused by Herpes simplex virus (HSV), presenting as
(1) monomorphic punched-out lesions
(2) requiring emergency same-day referral
9
Q
How does eczema present in adults?
A
- Generalised dryness
- Itching
- with hand eczema as a primary manifestation
10
Q
How does childhood eczema present?
A
Flexural distribution
(eg, inside elbows, behind knees)
11
Q
How does infantile eczema present?
A
(1) Primarily affects face, scalp, and extensor surfaces of limbs
(2) Nappy area is usually spared
12
Q
What is the cause of contact allergic dermatitis?
A
Type IV hypersensitivity reaction
(T-cell mediated) to an external antigen (eg - nickel, chemicals, plants)
= Features: Well-demarcated itchy, red, sometimes blistering rash at the contact site
13
Q
What is the cause of contact irritant dermatitis?
A
Non-specific physical irritation
eg - soap, water, cleaning products, nappy rash
= Features: Well-demarcated itchy, red, sometimes blistering rash at the contact site
14
Q
What is a key diagnostic clue for irritant contact dermatitis?
A
Flexures are spared in nappy rash (unlike in candidiasis)
15
Q
How does allergic contact dermatitis differ from irritant contact dermatitis?
A
Allergic = Rash spreads beyond the site of contact
Irritant = Rash is only at the site of exposure
Same features
16
Q
What investigation is used to diagnose contact allergic dermatitis?
A
Patch testing
(applying allergens to the back and checking reactions after 48–96 hours)
17
Q
What percentage of school-aged children are affected by atopic eczema?
A
Up to 25%
18
Q
What is the main genetic defect in atopic eczema?
A
Filaggrin gene mutation, leading to a defective skin barrier
19
Q
What other atopic diseases are associated with atopic eczema?
A
- Asthma
- Allergic rhinitis
- Food allergies
20
Q
What is the “itch-scratch cycle” in atopic eczema?
A
Scratching worsens the inflammation, leading to more itching and damage
21
Q
What is nodular prurigo?
A
- Very itchy
- Well-defined nodules
- Occurring in chronic atopic eczema
- More common in black individuals
22
Q
What are the diagnostic criteria for atopic eczema?
A
Itching plus 3 or more of:
(1) Visible flexural rash (or on cheeks/extensors in infants)
(2) History of flexural rash
(3) Personal history of atopy
(or family history if under 4 years old)
(4) Generally dry skin
(5) Onset before age 2
23
Q
What is the cause of discoid eczema?
A
- Coin-shaped
- Well-defined itchy plaques
- Often on the limbs and infected
- Can resemble fungal infections - tinea corporis
24
Q
What is seborrheic eczema?
A
- Greasy
- Scaly patches
- on the scalp, face (around nose/eyebrows/ ears), and chest
- Caused by an overgrowth of Malassezia yeast in sebaceous areas
- Associated with HIV and Parkinsons
- Cradle cap in babies
25
What is dyshidrotic eczema (pompholyx)?
1. Sudden acute eczema flare-up
2. Where vesicles join to form tiny
3. Intensely itchy blisters
4. On hands and feet
26
What is photo-induced eczema?
Eczema triggered by UV light, presenting with well-defined edges
= eg, collar-cut-off pattern
27
What is lichen simplex?
(Neurodermatitis)
Chronic eczema due to repetitive scratching leading to thickened skin (lichenification)
28
What is stasis (varicose) dermatitis?
1. Red
2. Swollen
3. Itchy skin
4. Around the lower legs and ankles
5. May develop ulcers
6. Eczema caused by venous insufficiency (poor circulation in the lower legs)
7. Seen in elderly patients with varicose veins
29
What general measures are recommended for eczema management?
1. Avoid triggers and irritants
2. Wear loose cotton clothing
3. Emollients (eg, Hydromol cream)
30
What is first-line treatment for mild eczema?
Topical steroids (mild potency)
31
What is the treatment for moderate eczema?
(1) Moderate topical steroid
= betamethasone valerate 0.025%
= clobetasone butyrate 0.05%
(2) Use mild steroids on the face
32
What is the treatment for severe eczema?
1. Potent topical steroid
= betamethasone valerate 0.1%
2. Moderate potency steroids for sensitive areas
3. Consider occlusive dressings
4. Treat infection if present
33
What treatment options are available in secondary care for severe eczema?
1. Phototherapy (UVB)
2. Systemic immunosuppression
3. Biologic agents
(eg, IL-4/IL-13 inhibitors for atopic eczema)
34
How is atopic dermatitis usually diagnosed?
Patch TEST
35
What nail signs are associated with eczema?
Irregular horizontal ridging
36
Which immunoglobulin has an elevated serum level in 80% of individuals with atopic eczema?
IgE
37
How long does a single course of topical steroid treatment typically last?
2 weeks
38
A 6-month-old boy presents to the GP with his mother. She is concerned because her son has developed a pruritic rash. On examination he has a dry, erythematous rash on his cheeks and the extensor aspects of both his elbows. He has previously been well and there are no concerns about his development. His mother reports also having pruritic rashes when she was young.
What is the most likely diagnosis?
Atopic Eczema
39
A 13-month-old girl is brought into the GP by her father. Her father reports that she has a background of eczema, however, over the last day, the eczema has quickly become worse and is extremely painful. The child is pyrexic and shivering. She is agitated throughout the consultation.
On examination, there are groups of fluid-filled blisters that break open and leave small, shallow open sores on the skin. Several ulcerations can be seen.
What is the most likely causative agent?
Herpes Simplex Virus (HSV)
40
A 22-year-old male has a chronic, pruritic rash on the flexor aspect of both elbows. On examination he has a symmetrical, erythematous, ill-defined rash with papules and vesicles. He manages his skin condition with regular emollients, which can be both troublesome and time-consuming. He wants to know more about what causes his skin condition.
What is the most likely explanation for the underlying cause of his skin condition?
A genetic defect in the skin barrier
41
What does Eczema Herpeticum present with?
1. widespread red
2. monomorphic blisters
3. erosions
42
A 12-month-old girl is brought to the Emergency Department with a new rash. Her parents report she has had eczema on her face before, but that this rash seems different. On examination, the girl has multiple red, monomorphic blisters and erosions across her face and neck. She appears unwell with a fever and local lymphadenopathy.
What is the most likely diagnosis, and what is the most appropriate initial management?
The most likely diagnosis is eczema herpeticum
(HSV infection superimposed on eczema)
= Management is:
(1) Intravenous Aciclovir
(2) Admission to hospital
(3) supportive care
43
A 7-year-old boy is brought to the General Practitioner by his mother with an itchy rash.
A similar rash is seen on his elbows. The General Practitioner prescribes an emollient and steroid cream.
What piece of information should be given to his mother regarding the application of the emollient?
1. Apply the emollient following a bath or a shower
2. Emollients should be gently smoothed into the skin, not rubbed
44
A 5-year-old boy is brought to the GP by his mother. She has noticed a rash on the creases of his elbows and behind his knees. It has been worsening over the past few weeks. The rash is very itchy and there are some excoriations on the affected areas. The patient has no past medical history. On examination, there is flaking and erythema at the flexures of the elbows and knees. There is no bleeding, altered pigmentation or signs of infection.
What is the best treatment option?
Hydromol cream and topical clobetasone butyrate 0.05%
45
A 21 year old Afro-Caribbean woman presents to her GP after developing a few small patches of pale skin over her elbow creases. She has a past medical history of atopic rhinitis and atopic dermatitis. During her last visit to the GP five weeks ago, she did not have this symptom. She had been prescribed a topical corticosteroid cream for her eczema. She takes no other medication and has no known drug allergies. Her mother struggles with hyperpigmentation and melasma. She does not smoke or drink alcohol.
What is the most likely cause of her symptoms?
Steroid-induced depigmentation
46
What is the main difference in the symptoms of Atopic Dermatitis vs Allergic Contact Dermatitis?
Atopic Dermatitis typically presents with
1. chronic
2. itchy
3. dry
4. inflamed skin
Allergic Contact Dermatitis presents as a
1. red
2. itchy rash
3. with swelling and blisters
4. with well-defined edges
47
How do the locations of the lesions differ between Atopic Dermatitis and Allergic Contact Dermatitis?
Atopic Dermatitis affects flexural areas
= like the elbows, knees, the face, and the neck.
Allergic Contact Dermatitis is localised to the area where the allergen made contact with the skin, such as hands, wrists, or around jewellery
48
A 24-year-old female presents to the GP with an itchy rash on her neck. She first noticed it after she started wearing a new necklace last week. She has no history of any skin conditions. On examination, there is an erythematous rash encircling her neck.
Given the most likely cause of her symptoms, which type of white blood cell is associated with this condition?
Patient has allergic contact dermatitis
= T lymphocytes
49
Eosinophils are associated with what type of conditions?
atopic dermatitis or asthma
50
A 30-year-old woman presents to the GP with an itchy rash on her wrists and forearms that is sometimes painful. She works as a cleaner and thinks it might be due to some of the products she is using, however, her boss is unable to provide alternatives for a long time. She is using gloves where possible. On examination, there is an erythematous rash visible on both wrists and forearms with mild fissuring.
What is the most appropriate management?
emollient usage
= doesn't need a patch test as we know the spruce of the problem
51
Mast cells are involved in what type of reactions?
Type I hypersensitivity reactions, such as those seen in anaphylaxis, urticaria, or allergic rhinitis
52
A 20-year-old female visits her GP due to a one-month history of itching and dryness on her face and scalp. She says these areas feel very irritated and sometimes sting. Although she usually has oily skin, her skin has felt very dry and flaky recently. The patient also has dandruff, which has not gone away with dandruff shampoos. She has no prior history of skin conditions and is otherwise well.
What is the most appropriate management for the likely diagnosis?
Ketoconazole shampoo
= In more severe cases use mild steroids
Disease is Seborrheic dermatitis
53
A 45-year-old woman has had a red, scaly rash on her face and scalp for several months. She describes it as greasy and flakey. The rash is itchy and flares up occasionally, often when she is stressed.
What is the most likely diagnosis?
Seborrhoeic dermatitis
54
A 33-year-old male presents with an itchy scalp which has been going on for a few weeks. He is normally fit and well but recently attended the GP for a widespread molluscum contagiosum rash which is resolving. On examination of the scalp, poorly defined flaky scales are visible with scattered erythematous patches.
What is the next most important step? and the steps after that?
Seborrhoeic Dermatitis – common in immunosuppressed patients (e.g. HIV)
1. HIV test → most important
2. Topical antifungal (ketoconazole shampoo or cream)
3. Mild topical steroid
= hydrocortisone 1% or betamethasone valerate 0.1%
→ Used only if there is significant inflammation to reduce redness and itching
55
A 42-year-old man presented with painful and itchy eyes.
On examination, he had erythema, crusting of the eyelid margins, and dry, flaky skin in the nasolabial folds. He reported that these symptoms worsen in the winter.
What is the mechanism underlying this condition?
Overgrowth of Malassezia
= patient has seborrhoeic dermatitis
56
What is the difference in appearance between Seborrhoeic dermatitis, Contact dermatitis and Atopic Dermatitis (Eczema)
Seborrhoeic dermatitis
= Greasy, yellowish scales with redness
Atopic Dermatitis (Eczema)
= Dry, red, cracked, inflamed skin, sometimes weeping
Contact Dermatitis
= Red, itchy rash, sometimes with blisters
57
Cradle Cap refers to what type of dermatitis?
Seborrhoeic Dermatitis
58
A mother brought her two-month-old son to the GP after noticing changes to the skin on his scalp. The baby appears well and does not seem to notice these changes. On examination, the image below is seen. There are no similar skin changes anywhere else on the baby's body.
What treatment would be the most appropriate for this baby's seborrhoeic/ Seborrheic dermatitis?
(1) Topical emollient + Topical Clotrimazole 1% as it's only in 1 area
(2) Can't use shampoo or steroids as too harsh
(3) Bathe the child in an emollient if evidence of seborrheic dermatitis in more than 1 area, especially the nappy area
59
A 4-month-old infant presents to the GP with a thick, yellowish scale on the scalp and eyebrows. The child is otherwise well, with no signs of distress or systemic illness. The parents report that the scales have been persistent for several weeks, despite daily bathing and shampooing with a mild baby shampoo. The rash is non-itchy, and there are no signs of infection.
What is the most appropriate next step in management?
Emollient application followed by gentle brushing
60
A 7-year-old child with mild atopic eczema is prescribed a topical steroid. Which of the following is the most appropriate first-line option?
A) Clobetasol propionate 0.05%
B) Betamethasone valerate 0.1%
C) Hydrocortisone 1%
D) Mometasone furoate 0.1%
C
= Hydrocortisone 1%
= Mild potency steroids are first-line for children with mild eczema to minimise side effects
61
A 35-year-old man with severe eczema on his hands is prescribed a very potent topical steroid. Which of the following is the most appropriate option?
A) Clobetasone butyrate 0.05% (Eumovate)
B) Betamethasone valerate 0.1% (Betnovate)
C) Mometasone furoate 0.1% (Elocon)
D) Clobetasol propionate 0.05% (Dermovate)
D
= Clobetasol propionate 0.05% (Dermovate)
62
Rank the topical corticosteroids used for eczema from least potent to most potent
Mild (Least Potent) – Class 1
(1) Hydrocortisone 0.5–2.5%
Moderate – Class 2
(1) Clobetasone butyrate 0.05% (Eumovate)
(2) Betamethasone valerate 0.025%
Potent – Class 3
(1) Betamethasone valerate 0.1% (Betnovate)
Very Potent – Class 4
(1) Clobetasol propionate 0.05% (Dermovate)
63
A 15-year-old female presents to ambulatory care with a painful pruritic rash that has rapidly worsened over the last 10 hours. Her past medical history includes atopic dermatitis treated with emollients and hay fever.
On examination, she has a monomorphic rash with punched-out erosions over her cheeks and bilateral dorsal wrists. She is admitted for IV antivirals and observation.
Which of the following is the most likely implicated pathogen?
A. Herpes simplex 1
B. Coxsackie virus A
C. Herpes zoster
D. Poxvirus
E. Human herpes virus 6
A
64
A 32-year-old woman has had an uncomfortable rash around her mouth for the past 2 months.
She uses a skin-cleansing face wash daily and also applies hydrocortisone 1% ointment twice a day. She has also spoken to a pharmacist who suggested clotrimazole 2% cream and has recently started using an old tube of fusidic acid cream.
She has also bought iron supplements after reading online that her symptoms may be attributable to iron deficiency. Despite all of this, she finds that her rash is worsening.
On examination, you notice clusters of papules with surrounding erythema around her mouth, with sparing of her lip margins. There are no comedones, cysts or nodules.
Which of her current treatments should be stopped as a priority?
Perioral dermatitis can be made worse by topical steroids so therefore
= Hydrocortisone
65
A 4-year-old child is brought to his GP with an area of multiple circular, depressed ulcerating lesions each measuring 1-3mm around his chin/neck region which his parent first noticed the day before. The child is otherwise well and the GP prescribes a topical emollient for a possible flare of his known atopic eczema.
Two days later the child is brought back in as the rash had increased in size and they have now developed diarrhoea and a fever.
What is the most appropriate treatment to commence?
The patient has developed Eczema herpeticum
= IV aciclovir
66
A 40-year-old Afro-Caribbean woman with a history of eczema has been applying a topical corticosteroid cream to her legs for several months to control flare-ups. While her eczema symptoms have lessened, she has observed the appearance of multiple light-coloured, irregularly shaped patches on her legs. These patches are lighter than the surrounding skin and are not associated with itching or burning sensations. Physical examination reveals well-defined, hypopigmented patches demarcated from the normal skin.
What is the most likely diagnosis?
Steroid use
= causes depigmentation
67
A 65-year-old woman with a history of Parkinson's disease presents to their general practitioner with a pruritic facial rash.
On examination, the patient has scaly erythematous lesions affecting the nasolabial folds and glabella.
What is the most likely diagnosis?
Seborrhoeic dermatitis
