A 35-year-old male presents with bald patches and with no scars. The patches are well demarcated with broken hair at the edges. Diagnosis is:
**Core Concept**
Alopecia areata is an autoimmune disease characterized by patchy hair loss due to the destruction of hair follicles by autoreactive T-cells. This condition is often associated with other autoimmune disorders, such as thyroid disease or vitiligo.
**Why the Correct Answer is Right**
In alopecia areata, the immune system mistakenly attacks the hair follicles, leading to a loss of hair in well-demarcated patches. The broken hair at the edges of the patches is a characteristic feature of this condition, as the hair growth cycle is disrupted, causing the hair to break off. The absence of scarring in alopecia areata is another key distinguishing feature, as the hair follicles are not destroyed, allowing for potential regrowth.
**Why Each Wrong Option is Incorrect**
**Option B:** Androgenic alopecia, also known as male pattern baldness, is a condition characterized by gradual hair thinning and loss, often with a distinctive pattern of recession at the temples. However, it does not typically present with well-demarcated patches of broken hair.
**Option C:** Discoid lupus erythematosus (DLE) is a chronic autoimmune skin condition that can cause scarring hair loss, particularly on the scalp. However, the hair loss in DLE is often accompanied by inflammation, erythema, and scarring, which is not present in alopecia areata.
**Option D:** Telogen effluvium is a condition characterized by excessive shedding of hair, often due to hormonal changes, stress, or other medical conditions. However, it typically presents with diffuse hair loss rather than well-demarcated patches.
**Clinical Pearl / High-Yield Fact**
Alopecia areata can be a marker for underlying autoimmune disease, and patients with this condition should be screened for other autoimmune disorders, such as thyroid disease or vitiligo.
✓ Correct Answer: A. Alopecia areata