Which of the following statements best describes the involvement of the immune system in psoriasis etiology?

Explanation: Immunosuppressive medications can weaken the immune system, making the patient more susceptible to infections. It is important for the patient to promptly report any signs of infection or illness to their healthcare provider for appropriate management.

Incorrect choices: b. The administration of immunosuppressive medications is often specific to each medication and should be taken as prescribed by the healthcare provider, with or without food, as indicated.

c. Immunosuppressive medications can increase the risk of infections, but they do not directly increase the risk of sunburn. Patients should, however, be cautious about sun exposure due to potential skin sensitivity.

d. Discontinuing immunosuppressive medications abruptly can be dangerous and should only be done under the guidance of a healthcare provider. Sudden discontinuation can lead to worsening of psoriasis and potential rebound effects.

Explanation: A skin biopsy is commonly performed to confirm the diagnosis of psoriasis. It involves taking a small sample of skin tissue from a psoriatic plaque and examining it under a microscope to identify the characteristic histological changes, such as hyperkeratosis, parakeratosis, and elongation of the rete ridges.

Incorrect choices: a. Skin patch testing for allergens: Patch testing is used to diagnose allergic contact dermatitis, not psoriasis.

b. Chest X-ray to assess lung involvement: Chest X-rays are not necessary for the diagnosis of psoriasis, as it primarily affects the skin and joints, not the lungs.

c. Complete blood count (CBC) to assess white blood cell count: While a CBC may be performed to assess inflammation, it is not specific to psoriasis and cannot confirm the diagnosis. A skin biopsy is needed for definitive diagnosis.