A CASE REPORT OF RARE DERMATOLOGIC CONDITION: TERRA FIRMA-FORME

Abstract

Background: Terra firma-forme dermatosis (TFFD) is a benign cutaneous condition characterized by persistent brown skin discoloration that is resistant to conventional washing but resolves with isopropyl alcohol. Due to its resemblance to other dermatological or systemic conditions, it is often misdiagnosed, leading to unnecessary treatments and patient anxiety.

Case Presentation: We report the case of Mariyah, a 17-year-old medically free Saudi female referred from an endocrinology clinic for persistent brown skin eruptions affecting her neck, axillae, inner thighs, abdomen, and chest for five years. The lesions, initially suspected to be an atypical presentation of acanthosis nigricans, were unresponsive to multiple topical whitening creams prescribed by various dermatologists. Upon presentation to our clinic, the affected areas were gently rubbed with gauze soaked in 70% isopropyl alcohol, resulting in almost complete clearance of the discoloration. This immediate resolution confirmed the diagnosis of TFFD. The patient was counseled on the benign nature of the condition and advised to use isopropyl alcohol to manage potential recurrences.

Conclusion: This case underscores the importance of recognizing TFFD as a differential diagnosis for persistent skin discoloration. The rapid diagnostic and therapeutic response to isopropyl alcohol demonstrates the simplicity of managing this condition and highlights the need for awareness among clinicians to prevent unnecessary treatments and investigations.