Title : Extensive terra firma-forme dermatosis in a healthy adult male: A rare and misleading presentation
Abstract:
Background: Terra firma-forme dermatosis (TFFD) is a benign yet frequently underdiagnosed cutaneous condition characterized by asymptomatic, dirt-like hyperpigmented plaques caused by retained keratinization. While commonly seen in children and typically affecting intertriginous areas, atypical and extensive adult presentations are rarely reported and may lead to unnecessary diagnostic workup.
Case Presentation: We present the case of a 25-year-old medically healthy male who reported multiple persistent, asymptomatic, hyperpigmented plaques over the anterior chest for approximately eight months. Despite regular hygiene, the lesions were refractory to soap and water, prompting dermatologic evaluation due to cosmetic concern. Cutaneous examination revealed multiple yellow-brown, verrucous plaques with well-defined borders and a characteristically dirty surface. Differential diagnoses included dermatosis neglecta, confluent and reticulated papillomatosis, and acanthosis nigricans. A diagnostic alcohol swab test using 70% isopropyl alcohol led to immediate and nearly complete resolution of the lesions, confirming TFFD. A punch biopsy performed prior to alcohol cleansing revealed classic histopathological findings, including lamellar hyperkeratosis, focal papillomatosis, mild acanthosis, and orthokeratotic whorls, with no significant dermal inflammation or infection.
Conclusion: This case highlights an uncommon and extensive presentation of TFFD on the anterior chest of an adult male, emphasizing the importance of clinical recognition of this condition. Prompt diagnosis via the alcohol swab test can prevent unnecessary investigations and interventions. Increased awareness among clinicians is essential to reduce misdiagnosis and ensure appropriate management of TFFD.
