ECZEMA AND DERMATITIS Flashcards
(30 cards)
Which of the following best describes atopic dermatitis (AD)?
A) A cutaneous manifestation of an atopic state associated with asthma and allergic rhinitis
B) A disorder exclusively affecting adults with no genetic predisposition
C) A bacterial skin infection caused by Staphylococcus aureus
D) A self-limited condition that only occurs in infants
Answer: A) A cutaneous manifestation of an atopic state associated with asthma and allergic rhinitis
Rationale: AD is described as the skin expression of the atopic state and is strongly associated with other atopic conditions like asthma and allergic rhinitis. It has a genetic predisposition and is not exclusively an adult disorder.
What is a characteristic genetic defect associated with the pathophysiology of atopic dermatitis?
A) Mutation in the filaggrin gene
B) Mutation in the CFTR gene
C) Deficiency of vitamin D receptors
D) Deficiency in ceramide production
Answer: A) Mutation in the filaggrin gene
Rationale: The text states that a mutation in the filaggrin gene, which encodes a structural protein in the stratum corneum, contributes to an impaired epidermal barrier, playing a crucial role in AD pathogenesis.
In adults with localized atopic dermatitis, which of the following features may suggest an underlying atopic condition?
A) Dennie-Morgan folds and increased palmar skin markings
B) Absence of pruritus
C) Exclusive involvement of the scalp
D) Sudden onset after 60 years of age
Answer: A) Dennie-Morgan folds and increased palmar skin markings
Rationale: The text mentions that in localized adult AD, typical features include Dennie-Morgan folds (an extra fold beneath the lower eyelid) and increased palmar skin markings, which are considered cutaneous stigmata of atopy.
Which of the following topical agents is NOT a glucocorticoid but is FDA-approved for the treatment of AD?
A) Hydrocortisone
B) Tacrolimus
C) Betamethasone
D) Clobetasol
Answer: B) Tacrolimus
Rationale: Tacrolimus is a topical calcineurin inhibitor (TCI), not a glucocorticoid. The text mentions that tacrolimus, pimecrolimus, and crisaborole are nonglucocorticoid agents approved for AD and do not cause skin atrophy.
Which of the following statements regarding secondary infections in AD is TRUE?
A) Secondary infections do not require antibiotic therapy.
B) Staphylococcus aureus is commonly responsible for secondary infections in AD.
C) The presence of eczematous lesions excludes the possibility of infection.
D) Methicillin-resistant Staphylococcus aureus (MRSA) infections are uncommon in AD.
Answer: B) Staphylococcus aureus is commonly responsible for secondary infections in AD.
Rationale: The text states that S. aureus frequently infects eczematous lesions, causing exacerbations of AD. It also mentions that more than 50% of S. aureus isolates are methicillin-resistant in some communities.
Which of the following systemic treatments is FDA-approved for severe AD and provides targeted immunomodulation with a favorable safety profile?
A) Cyclosporine
B) Methotrexate
C) Dupilumab
D) Azathioprine
Answer: C) Dupilumab
Rationale: The text states that dupilumab, an interleukin-4 receptor blocker, is FDA-approved for patients 6 years and older and offers more precise immunomodulation with fewer side effects compared to cyclosporine.
What is a potential limitation of using systemic glucocorticoids for AD treatment?
A) They are the most effective long-term treatment option.
B) They cause permanent remission of AD.
C) Stopping treatment often leads to worsening of AD.
D) They have no systemic side effects.
Answer: C) Stopping treatment often leads to worsening of AD.
Rationale: The text mentions that systemic glucocorticoids should be reserved for severe exacerbations, as discontinuation usually results in relapse or worsening of AD.
What is the primary difference between irritant contact dermatitis (ICD) and allergic contact dermatitis (ACD)?
A) ICD is an immune-mediated reaction, while ACD is due to direct chemical injury.
B) ICD requires prior exposure, while ACD does not.
C) ACD is caused by an antigen-specific immune response, while ICD is caused by the inherent properties of a substance.
D) Both ICD and ACD have the same pathophysiology and require prior sensitization.
Answer: C) ACD is caused by an antigen-specific immune response, while ICD is caused by the inherent properties of a substance.
Rationale: The key distinction is that ICD results from direct injury by an irritant (e.g., acids, soaps, detergents), whereas ACD is a delayed hypersensitivity reaction requiring prior sensitization.
What is the most commonly affected body part in chronic irritant contact dermatitis (ICD)?
A) Eyelids
B) Hands
C) Face
D) Feet
Answer: B) Hands
Rationale: Chronic wet work, soaps, and detergents are common irritants in ICD, and the hands are the most frequently affected area due to repeated exposure.
How long does it take for an allergic contact dermatitis reaction to develop after exposure to an allergen like poison ivy?
A) Immediately upon contact
B) 5–10 minutes
C) 12–72 hours
D) 7–10 days
Answer: C) 12–72 hours
Rationale: ACD is a delayed-type hypersensitivity reaction mediated by memory T cells, which means symptoms develop 12–72 hours after exposure.
Which of the following best describes a typical rash caused by poison ivy exposure?
A) Circular plaques with well-defined borders
B) Linear or angular lesions with vesiculation and severe pruritus
C) Scaly patches with thickened skin
D) Widespread petechial rash
Answer: B) Linear or angular lesions with vesiculation and severe pruritus
Rationale: The linear or angular appearance corresponds to direct skin contact with the plant, which deposits urushiol along its path, leading to a vesicular, intensely pruritic rash.
Which of the following is TRUE regarding irritant contact dermatitis (ICD)?
A) It requires prior exposure to the irritant.
B) Symptoms appear minutes to hours after exposure.
C) It is mediated by memory T lymphocytes.
D) It is most commonly caused by poison ivy.
Answer: B) Symptoms appear minutes to hours after exposure.
Rationale: Unlike ACD, which requires prior sensitization, ICD occurs rapidly (within minutes to hours) as a direct result of chemical injury to the skin.
What is the primary treatment strategy for irritant contact dermatitis?
A) Systemic glucocorticoids
B) Avoidance of irritants and protective measures (e.g., gloves, clothing)
C) Antibiotics
D) Antihistamines
Answer: B) Avoidance of irritants and protective measures (e.g., gloves, clothing)
Rationale: The best way to manage ICD is by avoiding the offending irritant, using protective gloves/clothing, and minimizing exposure to harsh chemicals.
What is the first-line treatment for contact dermatitis after the offending agent has been identified and removed?
A) Systemic glucocorticoids
B) High-potency topical glucocorticoids
C) Antihistamines
D) Antibiotics
Answer: B) High-potency topical glucocorticoids
Rationale: Once the irritant or allergen is removed, high-potency topical glucocorticoids are usually sufficient to control inflammation and symptoms while the dermatitis resolves.
If systemic therapy is required for severe contact dermatitis, what is the recommended oral prednisone regimen?
A) 5 mg/kg daily, tapered over 1 week
B) 1 mg/kg daily (≤60 mg/d), tapered over 2–3 weeks
C) 50 mg every other day for 10 days
D) 100 mg daily for 1 week, then abrupt discontinuation
Answer: B) 1 mg/kg daily (≤60 mg/d), tapered over 2–3 weeks
Rationale: Systemic prednisone (≤60 mg/d) is used for severe cases and should be tapered over 2–3 weeks to prevent rebound dermatitis.
Which of the following situations should raise suspicion for allergic contact dermatitis (ACD)?
A) A rash that resolves quickly with moisturizers
B) Dermatitis unresponsive to conventional therapy or with a patterned distribution
C) Immediate onset of a rash within minutes of exposure
D) A well-demarcated rash limited to the hands after wet work
Answer: B) Dermatitis unresponsive to conventional therapy or with a patterned distribution
Rationale: ACD should be suspected when dermatitis persists despite standard treatments or has an unusual, patterned distribution that suggests contact with an allergen.
Which of the following is TRUE regarding patch testing for allergic contact dermatitis (ACD)?
A) It should be performed when the patient has widespread active dermatitis.
B) It is the best method to identify the responsible allergen.
C) Systemic glucocorticoids must be used before patch testing.
D) Patch testing is only used for irritant contact dermatitis (ICD).
Answer: B) It is the best method to identify the responsible allergen.
Rationale: Patch testing helps identify specific allergens in ACD but should not be done when patients have widespread active dermatitis or are on systemic glucocorticoids, which could suppress reactions.
When should systemic glucocorticoids be used for contact dermatitis?
A) For all cases of contact dermatitis
B) Only when the dermatitis is severe or widespread
C) When the patient does not want to use topical treatments
D) As a first-line treatment for mild cases
Answer: B) Only when the dermatitis is severe or widespread
Rationale: Systemic glucocorticoids (e.g., prednisone) are reserved for severe cases when topical therapy is insufficient, due to risks of systemic side effects.
Which of the following is a common trigger for hand eczema?
A) Genetic mutations in filaggrin
B) Excessive exposure to water and detergents
C) Deficiency in vitamin D
D) Excessive sun exposure
Answer: B) Excessive exposure to water and detergents
Rationale: Chronic exposure to water, detergents, and harsh chemicals can disrupt the skin barrier, leading to hand eczema, particularly in individuals with occupational exposures.
Which of the following is a key feature of dyshidrotic eczema, a variant of hand eczema?
A) Large bullous lesions on the dorsal hand
B) Small, intensely pruritic vesicles on the palms and sides of the fingers
C) Well-demarcated erythematous plaques with silvery scales
D) Crusted ulcers forming on the nail beds
Answer: B) Small, intensely pruritic vesicles on the palms and sides of the fingers
Rationale: Dyshidrotic eczema presents with small vesicles (blisters) on the thenar and hypothenar eminences and fingers, which are extremely itchy and occur in crops.
What is the best initial treatment approach for hand eczema?
A) Daily systemic glucocorticoids
B) Application of high-potency topical glucocorticoids and avoidance of irritants
C) Use of oral antihistamines as monotherapy
D) Frequent hand washing with antibacterial soap
Answer: B) Application of high-potency topical glucocorticoids and avoidance of irritants
Rationale: First-line treatment includes avoiding triggers and using topical glucocorticoids to reduce inflammation.
If secondary infection is suspected in hand eczema, which diagnostic test should be performed?
A) Biopsy with hematoxylin and eosin staining
B) Potassium hydroxide (KOH) preparation and culture
C) Patch testing
D) Wood’s lamp examination
Answer: B) Potassium hydroxide (KOH) preparation and culture
Rationale: Secondary dermatophyte infection should be ruled out using KOH prep and culture in patients with chronic hand eczema.
What is the characteristic appearance of nummular eczema?
A) Thickened, hyperpigmented plaques
B) Circular or oval “coin-like” lesions
C) Pruritic vesicles in a linear pattern
D) Large bullous lesions on the lower extremities
Answer: B) Circular or oval “coin-like” lesions
Rationale: Nummular eczema is distinguished by coin-shaped plaques that begin as small, edematous papules and later become crusted and scaly
Asteatotic eczema is commonly referred to as:
A) Nummular eczema
B) Xerotic eczema or “winter itch”
C) Allergic contact dermatitis
D) Stasis dermatitis
Answer: B) Xerotic eczema or “winter itch”
Rationale: Asteatotic eczema occurs due to extremely dry skin, particularly in the winter months, leading to fine cracks, scaling, and pruritus.
