Pityriasis Rosea

A 28-year-old woman presents with a 2-week history of a solitary, asymptomatic, scaly patch on her left upper back. She reports mild pruritus. One week later, she develops a widespread eruption of small, oval, scaly papules and plaques on her trunk and proximal limbs, distributed along Langer's lines. The lesions are salmon-pink in colour. She denies fever, arthralgia, or recent upper respiratory infection. Serological testing for syphilis is negative. What is the most likely diagnosis?

A 35-year-old man from Delhi presents with a 3-week history of an itchy rash on his trunk. He recalls a single, slightly raised, scaly lesion on his left shoulder that appeared 10 days before the generalized rash developed. Physical examination reveals numerous small, oval, salmon-coloured papules and plaques distributed on his chest, abdomen, and back in a pattern that follows the natural skin fold lines. The lesions are mildly pruritic. Histopathology shows focal parakeratosis, mild spongiosis, and superficial perivascular lymphocytic infiltrate. What is the most appropriate next step in management?

A 22-year-old woman presents with a 2-week history of an asymptomatic rash on her trunk. She recalls a single larger oval patch on her chest 1 week ago, followed by the appearance of numerous smaller lesions spreading across her back and upper arms. Examination reveals multiple oval, salmon-colored, finely scaly patches with a collarette of scale at the edges, oriented along skin cleavage lines in a Christmas-tree distribution as shown by the lesions marked **A** in the diagram. Palms, soles, and mucous membranes are spared. RPR and HIV serology are negative. What is the most likely diagnosis?

A 28-year-old woman presents with a 2-week history of a solitary, asymptomatic, scaly patch on her left shoulder. She reports mild pruritus. One week later, she develops a widespread eruption of small, oval, scaly papules and plaques on her trunk and proximal limbs, distributed along the lines of skin cleavage. The lesions are predominantly on the trunk with a "Christmas tree" distribution. She denies fever, arthralgia, or recent drug exposure. Serological tests for syphilis are negative. What is the most likely diagnosis?

A 22-year-old male student presents with a 3-week history of an itchy rash on his trunk and arms. He recalls a single, scaly patch on his upper back 10 days before the widespread eruption began. Examination reveals numerous small, oval, erythematous papules with a fine, adherent scale distributed over the chest, back, and proximal arms in a linear pattern along skin tension lines. He is otherwise well, with no fever or lymphadenopathy. A KOH mount of scale is negative. Which of the following is the most appropriate next step in management?