Differential Diagnosis for Unilateral Follicle Rash in Nasolabial Fold

Single Most Likely Diagnosis

• Perioral dermatitis: This condition is characterized by a rash around the mouth, which can include the nasolabial fold. It's often seen in young women and can be exacerbated by topical steroids, makeup, and certain medications. The patient's use of various topical treatments (mupirocin, neosporin) might have contributed to the development or persistence of the rash.

Other Likely Diagnoses

• Acne: Given the location in the nasolabial fold and the description of a follicle rash, acne is a plausible diagnosis. The patient's age and the unilateral presentation are consistent with this condition.
• Rosacea: This chronic skin condition can cause redness, pimples, and swelling, often affecting the face, including the nasolabial fold. The patient's symptoms could be consistent with a subtype of rosacea, especially given the localized nature of the rash.
• Contact dermatitis: The patient has used several topical treatments (doxycycline, mupirocin, neosporin), any of which could potentially cause an allergic or irritant contact dermatitis, especially if used inappropriately or in sensitive areas.

Do Not Miss Diagnoses

• Lupus miliaris disseminatus faciei (LMDF): Although rare, LMDF is a granulomatous condition that can present with a facial rash, including the nasolabial fold. It's essential to consider this diagnosis due to its potential for scarring and the need for specific treatment.
• Sarcoidosis: This systemic disease can cause skin lesions, including those on the face. While less common, sarcoidosis is a critical diagnosis not to miss due to its potential systemic implications and the need for comprehensive management.
• Tuberculosis (cutaneous): Cutaneous tuberculosis can manifest in various forms, including a facial rash. Given the patient's use of immunomodulatory therapy (Rinvoq), the risk of reactivation of latent tuberculosis might be increased, making this a crucial diagnosis not to overlook.

Rare Diagnoses

• Demodex folliculitis: Caused by the Demodex mite, this condition can lead to a follicular rash, particularly in the facial area. It's less common but should be considered in cases where other treatments have failed.
• Granulomatous perioral dermatitis: A variant of perioral dermatitis with granulomatous features, this condition can present with a more persistent and treatment-resistant rash, often requiring biopsy for diagnosis.