Differential Diagnosis for Small Red Bumps with White Center on Thighs and Buttocks in Adult
Single Most Likely Diagnosis
- Keratosis Pilaris: This condition is characterized by small, rough, sandpaper-like bumps on the skin, often with a white center, and typically appears on the thighs, buttocks, and arms. It's a common, benign condition that matches the description provided.
Other Likely Diagnoses
- Folliculitis: An inflammation of the hair follicles, which can cause small, red bumps, sometimes with a white center (pustule), especially in areas prone to friction and sweating like the thighs and buttocks.
- Pityriasis Rosea: Although it often starts with a herald patch, this condition can present with small, red bumps, some of which may have a white center. It typically appears on the trunk but can spread to other areas.
- Milia: Small, white or yellowish bumps on the skin that can sometimes appear red if inflamed, though they are not typically described with a white center, they could be considered if the description is slightly off.
Do Not Miss Diagnoses
- Malignant Melanoma or Other Skin Cancers: Although rare and less likely given the description of multiple small bumps, any new or changing skin lesion should be evaluated for the possibility of skin cancer, as early detection is crucial.
- Infectious Diseases (e.g., MRSA, Impetigo): Certain infectious diseases can cause skin lesions that might fit the description. These conditions can spread and have significant health implications if not treated promptly.
Rare Diagnoses
- Syringomas: Benign tumors of the sweat glands that can appear as small, firm, yellowish or translucent bumps, sometimes with a red appearance if inflamed, but not typically with a white center.
- Lichen Nitidus: A rare skin condition characterized by tiny, shiny, flat-topped bumps that can appear in clusters, often on the arms, chest, abdomen, buttocks, and genitals. The bumps are usually flesh-colored but can appear red if inflamed.
- Papular Urticaria: An itchy rash (though the question specifies non-itchy, this could be an exception) caused by an allergic reaction to insect bites, which could potentially present with small red bumps, though typically they are more scattered and related to bite history.