Psoriasis Vulgaris — MCQs
HLA-Cw6 is associated with
Acrodermatitis continua of Hallopeau is due to which of the following?
The important feature of psoriasis is –
A patient with psoriasis was started on systemic steroids. After stopping treatment, the patient developed generalized pustules all over the body. The cause is most likely to be:
Which one of these should not be used in severe widespread psoriasis?
A 30-year-old male presented with silvery scales on elbow and knee, that bleed on removal. The probable diagnosis is:
Which of the following nail findings is seen in the condition shown below?
Which statement about systemic steroids in psoriasis is correct:
A 54-year-old man presents with well-demarcated, erythematous plaques covered with silvery-white scales on the extensor surfaces of his elbows and knees. What is the most likely diagnosis?
Koebner's phenomenon is seen in all of the following, except?
Psoriasis Vulgaris Indian Medical PG Practice Questions and MCQs
Question 1: HLA-Cw6 is associated with
- A. Behcet's disease
- B. Pemphigus vulgaris
- C. Psoriasis vulgaris (Correct Answer)
- D. Myasthenia gravis
Explanation: ***Psoriasis vulgaris*** - **HLA-Cw6** is the **strongest genetic risk factor** associated with an increased susceptibility to psoriasis vulgaris, particularly early-onset forms. - Its presence is linked to a more severe and widespread presentation of the disease. *Myasthenia gravis* - This autoimmune disorder is primarily associated with **HLA-DR3** and **HLA-B8**, and autoantibodies against the acetylcholine receptor. - While other HLA alleles may be involved, **HLA-Cw6** is not a primary or strong genetic association for myasthenia gravis. *Behcet's disease* - **HLA-B51** is the most significant genetic association with Behcet's disease, particularly in populations of Middle Eastern and East Asian descent. - Symptoms include **recurrent oral and genital ulcers**, **uveitis**, and skin lesions. *Pemphigus vulgaris* - This autoimmune blistering disease is strongly associated with **HLA-DR4** and **HLA-DRw6**, especially in individuals of Jewish descent. - It involves autoantibodies targeting **desmoglein 1 and 3**, leading to acantholysis within the epidermis.
Question 2: Acrodermatitis continua of Hallopeau is due to which of the following?
- A. Zinc toxicity
- B. Zinc deficiency
- C. Collodion baby
- D. Pustular psoriasis (Correct Answer)
Explanation: ***Pustular psoriasis*** - **Acrodermatitis continua of Hallopeau** is considered a severe, chronic, and localized variant of **pustular psoriasis** that primarily affects the distal extremities, particularly the nail beds and fingertips. - It involves recurrent outbreaks of **sterile pustules** that can lead to onychodystrophy, anonychia, and bone resorption. *Zinc toxicity* - **Zinc toxicity** can cause symptoms such as nausea, vomiting, abdominal pain, and copper deficiency, but it is not linked to acrodermatitis continua of Hallopeau. - Dermatological manifestations of zinc toxicity are generally not pustular or associated with nail and digit changes seen in this condition. *Zinc deficiency* - **Zinc deficiency** can lead to acrodermatitis enteropathica, a condition characterized by periorificial and acral dermatitis, alopecia, and diarrhea. - While it involves skin involvement in similar areas, the primary lesions are **eczematous and psoriasiform**, not typically sterile pustules as seen in acrodermatitis continua. *Collodion baby* - **Collodion baby** refers to a newborn covered by a taut, shiny membrane that resembles plastic wrap, typically associated with congenital ichthyoses. - It is a specific neonatal presentation of a skin barrier defect and is not related to acrodermatitis continua of Hallopeau or pustular skin conditions.
Question 3: The important feature of psoriasis is –
- A. Oozing
- B. Crusting
- C. Scaling (Correct Answer)
- D. Erythema
Explanation: ***Scaling*** - Psoriasis is characterized by **erythematous plaques** covered with **silvery-white scales**, which is the **hallmark and most distinguishing feature** of the condition. - These scales result from **accelerated epidermal turnover** (3-4 days vs. normal 28 days) causing **hyperproliferation and abnormal differentiation of keratinocytes**. - The **Auspitz sign** (pinpoint bleeding upon scale removal) is a classic diagnostic feature. - Scaling is what differentiates psoriasis from other erythematous conditions. *Oozing* - **Oozing**, also known as weeping, is typically associated with acute inflammatory skin conditions, such as **acute eczema** or **bacterial infections**. - It indicates the presence of serous exudate from the skin, which is not a primary feature of psoriasis. *Crusting* - **Crusting** involves dried serum, blood, or pus on the skin surface and is commonly seen in conditions like **impetigo** or healing wounds. - While secondary infections can occur in psoriatic lesions, crusting itself is not a defining characteristic. *Erythema* - **Erythema**, or redness, is indeed present in psoriatic plaques, but it is not the *most important distinguishing feature*. - Many inflammatory skin conditions cause erythema, so it is a non-specific finding without the presence of prominent scaling.
Question 4: A patient with psoriasis was started on systemic steroids. After stopping treatment, the patient developed generalized pustules all over the body. The cause is most likely to be:
- A. Drug induced reaction
- B. Septicemia
- C. Pustular psoriasis (Correct Answer)
- D. Bacterial infections
Explanation: ***Pustular psoriasis*** - The sudden withdrawal of **systemic corticosteroids** in a patient with psoriasis can trigger a severe flare-up, specifically **generalized pustular psoriasis** (GPP), characterized by widespread sterile pustules. - GPP is a distinct, severe form of psoriasis that can be precipitated by various factors, including drug withdrawal. *Drug induced reaction* - While steroids themselves can have side effects, the development of **generalized pustules** shortly after stopping treatment in a known psoriasis patient points more specifically to a paradoxical worsening of their underlying disease rather than a general drug reaction. - Drug-induced reactions are typically directly related to the drug's properties or an allergic response, whereas this scenario describes an exacerbation of the existing condition due to treatment cessation. *Septicemia* - Septicemia, or **sepsis**, would present with signs of systemic infection such as **fever, chills, hypotension, and organ dysfunction**, which are not explicitly mentioned as the primary cause of the pustules. - While severe GPP can lead to systemic symptoms and potentially secondary infections, the initial development of pustules post-steroid withdrawal is a primary dermatological event, not directly caused by septicemia. *Bacterial infections* - **Bacterial infections** would typically manifest with purulent pustules, often with signs of inflammation, pain, and potentially fever. These pustules would contain bacteria upon Gram stain and culture. - The pustules in **pustular psoriasis** are typically sterile, meaning they do not contain bacteria, and their appearance is a manifestation of the underlying autoimmune inflammatory process exacerbated by steroid withdrawal.
Question 5: Which one of these should not be used in severe widespread psoriasis?
- A. Methotrexate
- B. Oral retinoids
- C. Cyclosporin
- D. Oral glucocorticoids (Correct Answer)
Explanation: ***Oral glucocorticoids*** - While they may provide temporary relief, **oral glucocorticoids** can exacerbate psoriasis upon withdrawal, leading to a severe flare-up or **pustular psoriasis**. - Their long-term use is associated with numerous side effects, making them unsuitable for widespread, chronic conditions like severe psoriasis. *Methotrexate* - **Methotrexate** is a systemic agent commonly used for severe psoriasis due to its immune-modulating and anti-proliferative effects. - It is effective in reducing inflammation and slowing down epidermal cell turnover. *Oral retinoids* - **Oral retinoids** like acitretin are effective systemic treatments for severe widespread psoriasis, especially **pustular** and **erythrodermic** forms. - They work by normalizing keratinocyte proliferation and differentiation. *Cyclosporin* - **Cyclosporin** is a potent immunosuppressant widely used for severe psoriasis, particularly when rapid disease control is needed. - It works by inhibiting T-cell activation and is highly effective in clearing psoriatic lesions.
Question 6: A 30-year-old male presented with silvery scales on elbow and knee, that bleed on removal. The probable diagnosis is:
- A. Secondary syphilis
- B. Psoriasis (Correct Answer)
- C. Pityriasis
- D. Seborrhoeic dermatitis
Explanation: ***Psoriasis*** - The presence of **silvery scales** on the elbows and knees, which **bleed upon removal** (Auspitz sign), is a classic presentation of **plaque psoriasis**. - Psoriasis is a chronic inflammatory skin condition characterized by **accelerated epidermal turnover**. *Secondary syphilis* - Secondary syphilis typically presents with a **generalized maculopapular rash**, which can affect the palms and soles, but it does not usually feature silvery scales or the Auspitz sign. - Other common symptoms of secondary syphilis include **fever, lymphadenopathy, and condyloma lata**. *Pityriasis* - **Pityriasis rosea** is characterized by an oval, fawn-colored, scaly rash, often preceded by a **herald patch**, and usually resolves spontaneously. It does not typically present with silvery scales or bleeding on removal. - **Pityriasis versicolor** is caused by yeast and presents as hypopigmented or hyperpigmented macules with fine scales, commonly on the trunk, not silvery scales on elbows and knees. *Seborrhoeic dermatitis* - Seborrhoeic dermatitis involves greasy, yellowish scales on red skin, typically affecting areas rich in sebaceous glands like the scalp, face (nasolabial folds, eyebrows), and chest. - It does not present with silvery scales or the Auspitz sign, which are specific to psoriasis.
Question 7: Which of the following nail findings is seen in the condition shown below?
- A. Pterygium
- B. Pigmentation
- C. Pitting (Correct Answer)
- D. Ridges
Explanation: ***Pitting*** - The image displays multiple small, **punctate depressions** on the nail plate, which are characteristic features of nail pitting. - Nail pitting is a common finding in conditions affecting the **nail matrix**, such as psoriasis. *Pterygium* - **Pterygium** refers to the forward growth of the proximal nail fold onto the nail plate, or the lateral nail folds onto the nail plate, often leading to nail loss. - This is not observed in the image, which primarily shows depressions rather than overgrowth of skin onto the nail. *Pigmentation* - **Nail pigmentation** involves discoloration of the nail plate, appearing as streaks, spots, or diffuse changes in color (e.g., brown, black, blue). - The nail in the image does not show abnormal discoloration but rather surface irregularities. *Ridges* - **Ridges** in nails (longitudinal or transverse) are linear elevations or grooves on the nail surface. - While some linear texture is present, the predominant feature in the image is distinct, small, and scattered depressions, which are consistent with pitting rather than continuous ridges.
Question 8: Which statement about systemic steroids in psoriasis is correct:
- A. No definitive indication exists (Correct Answer)
- B. Only as bridge therapy in rare cases
- C. Emergency situations under specialist supervision only
- D. Systemic steroids are contraindicated in all forms of psoriasis
Explanation: ***No definitive indication exists*** - Systemic steroids have **no established therapeutic role** in psoriasis management and are **strongly avoided** in clinical practice. - They can cause severe **rebound flares** upon withdrawal and may precipitate life-threatening **pustular psoriasis** or **erythrodermic psoriasis**. - While not absolutely contraindicated in every conceivable scenario, they provide **no long-term benefit** and actively worsen disease control by masking symptoms and creating dependency. - This statement most accurately reflects the medical consensus: systemic steroids lack definitive indications and should be avoided. *Systemic steroids are contraindicated in all forms of psoriasis* - While systemic steroids are strongly discouraged, the absolute term "contraindicated in **all forms**" is **too extreme**. - There may be rare emergency situations where short-term use under specialist care is considered when safer alternatives are unavailable. - The statement overstates the position; "no definitive indication" is more medically accurate. *Only as bridge therapy in rare cases* - Bridge therapy with systemic steroids is **not recommended** in psoriasis due to high risk of disease exacerbation. - Unlike other inflammatory conditions, psoriasis responds poorly to steroid withdrawal, making bridge therapy particularly dangerous. *Emergency situations under specialist supervision only* - This suggests systemic steroids have a defined role in emergencies, which is **misleading**. - Even in urgent situations, alternative treatments like **cyclosporine**, **methotrexate**, or **biologics** are strongly preferred. - The rare exceptions don't constitute a "definitive indication."
Question 9: A 54-year-old man presents with well-demarcated, erythematous plaques covered with silvery-white scales on the extensor surfaces of his elbows and knees. What is the most likely diagnosis?
- A. Pityriasis rosea
- B. Psoriasis (Correct Answer)
- C. Eczema
- D. Lichen planus
Explanation: ***Psoriasis*** - **Psoriasis** classically presents with **scaly plaques** that often appear on the **extensor surfaces** such as the elbows and knees. - The scales are typically silvery-white and can be itchy or painful, consistent with the characteristic presentation of chronic plaque psoriasis. *Pityriasis rosea* - This condition presents with a **herald patch** followed by smaller, oval, pinkish-red patches with fine scales, often distributed in a **Christmas tree pattern** on the trunk. - It primarily affects the trunk and proximal extremities, rarely involving the extensor surfaces in the same way as psoriasis. *Eczema* - **Eczema**, particularly atopic dermatitis, typically presents with **itchy, erythematous patches** that are often ill-defined and can be dry or weeping. - While it can occur on extensor surfaces, it is more commonly found on flexural surfaces in adults and lacks the distinct, thick silvery scales characteristic of psoriasis. *Lichen planus* - **Lichen planus** is characterized by **pruritic, purple, polygonal, planar papules and plaques** (**the 6 P's**). - It usually affects the flexural surfaces, wrists, ankles, and oral mucosa, rather than predominantly presenting as scaly plaques on extensor surfaces.
Question 10: Koebner's phenomenon is seen in all of the following, except?
- A. Lichen Planus
- B. Vitiligo
- C. Psoriasis
- D. Herpes (Correct Answer)
Explanation: ***Herpes*** - **Koebner's phenomenon**, also known as the isomorphic response, involves the development of new skin lesions at sites of trauma. It is not characteristic of **herpes simplex virus (HSV)** infections. - Herpes lesions typically appear in a dermatomal distribution or as localized clusters due to **viral replication** and spread, not trauma. *Lichen Planus* - **Lichen planus** is well-known for exhibiting Koebner's phenomenon, where new papules or plaques can emerge along scratch lines or other areas of skin injury. - This response is thought to be mediated by the **immunological activation** of keratinocytes in response to trauma. *Vitiligo* - **Vitiligo** often demonstrates Koebner's phenomenon, where new depigmented patches can develop in areas of skin trauma like cuts, abrasions, or burns. - This suggests that injury can trigger auto-immune destruction of **melanocytes** in susceptible individuals. *Psoriasis* - **Psoriasis** is a classic example of a condition exhibiting Koebner's phenomenon, with new psoriatic plaques appearing at sites of skin injury, such as scratches, surgical incisions, or sunburns. - This phenomenon highlights the role of **trauma** in triggering or exacerbating inflammatory skin conditions in genetically predisposed individuals.
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