MCQ – 69035

Correct Answer » A Explanation

Anatomical Role
– Patchy hair loss involves the hair follicles, typically sparing follicle structure but causing non-scarring alopecia.
– Skin texture changes like velvety skin suggest associated autoimmune or endocrine involvement.

Clinical Reasoning for the Correct Answer
– Alopecia Areata is a common cause of patchy non-scarring hair loss, characterized by well-demarcated circular bald patches.
– Patients may have coexisting autoimmune conditions or skin changes like velvety, smooth skin due to autoimmune or trophic changes, supporting this diagnosis.
– Velvety skin can also occur due to localized areas of lichenification or subtle thickening often associated with alopecia areata.
– No signs of hair shaft damage or behavioral causes are described, favoring alopecia areata.

Why Option A is Correct
– Patchy, well-defined non-scarring hair loss matches alopecia areata.
– Velvety skin texture may occur due to autoimmune inflammation affecting the scalp skin.

Why Option B is Incorrect
– Trichotillomania is a psychogenic hair-pulling disorder with irregular, broken hair shafts and uneven alopecia patches.
– It lacks velvety skin and often shows “frayed” hair shafts on examination.
– The patient history usually reveals compulsive hair pulling.

Why Option C is Incorrect
– Hyperthyroidism usually causes diffuse hair thinning and fine, soft hair, without patchy hair loss.
– Skin in hyperthyroidism is classically warm, moist, and smooth, not velvety.
– Additional systemic signs are expected (tachycardia, heat intolerance).

Why Option D is Incorrect
– Sebaceous adenoma is a benign tumor of sebaceous glands, presenting as a yellowish papule or nodule, not patchy hair loss.
– It does not cause diffuse or patchy alopecia or skin texture changes like velvety skin.
– This is a localized lesion, not a scalp-wide condition.