Causes
Injuries of the forearm with compression of the nerve from swelling is the most common cause: examples include supracondylar fractures, often associated with haemorrhage into the deep musculature; injury secondary to open reduction of a forearm fracture; or dislocation of the elbow.⁠⁠Direct trauma from a penetrating injury such as a stab wound is a possible cause for the syndrome.Fibrous bands or Arcuate ligament~arcuate (curved) ligaments may entrap the median as well as the anterior interosseous nerve, in which case a patient may experience hand numbness as well as wrist pain.⁠⁠Very similar syndromes can be caused by more proximal lesions, such as brachial plexus neuritis.⁠Anterior interosseous nerve entrapment or compression injury remains a difficult clinical diagnosis because it is mainly a motor nerve problem, and the syndrome is often mistaken for index finger and/or thumb tendon injury.⁠

Anatomy
The anterior interosseous nerve is a branch of the median nerve, with a large sensory branch to the wrist bones, which arises just below the elbow. It passes distally, anteriorly along the interosseous membrane and innervates flexor pollicis longus, flexor digitorum profundus to index and middle finger as well as pronator quadratus, and supplies sensory feedback from the wrist bones, i.e. the carpal tunnel, not skin. Diagnosis
Electrophysiologic testing is an essential part of the evaluation of anterior interosseous nerve syndrome.
Diagnosis
A positive culture in MacConkey agar is diagnostic, but cultures are only positive in 50–60% of cases. Diagnostic characteristics are most commonly found in the granulomatous stage and are described as being plasma cells with birefringent inclusions, Russell bodies, pseudoepitheliomatous hyperplasia, and groups of large vacuolated histiocytes containing Klebsiella rhinoscleromatis (Mikulicz cells). Treatment
It is not lethal in nature and is responsive to tetracycline or ciprofloxacin. Surgical treatment include rhinoplasty. However, if left untreated the disease can lead to sepsis, bleeding, or other chronic conditions that can be fatal. History
Hans von Hebra (1847–1902) wrote the classical description of the disease in a paper published in the January 1870 issue of the Wiener Medizinische Wochenschrift. Hans von Hebra was the son of Czech born dermatologist Ferdinand Ritter von Hebra (1816–1880), founder of the New Vienna School of Dermatology. He was assisted by M. Kohn who provided much of the histology for the paper. M. Kohn is the birth name of Moritz Kaposi (1837–1902). In 1876, Mikulicz contributed to the microscopic histology. In 1882, Anton Von Frisch (1849–1917) discovered the gram-negative bacillus which causes the disease. Terminology
Hebra nose. Scleroma. Fr: Sclérome. Sp: Rinoscleroma. Ger: Sklerom. Nasen-Rachenrauminduration.Archaic terms include: Syphilis of the nose. Nasal leprosy. Scleroma neonatorum. Scleroma respiratorum. Scrofulous lupus. See also
Erythrasma
List of cutaneous conditions
List of inclusion bodies that aid in diagnosis of cutaneous conditions

Notes
References
DiBartolomeo, Joseph R. (1976), Scleroma of the nose and pharynx. Journal: West. J. Med., vol. 124., pp. 13–17. Frisch, Anton von (1882), Zur Aetiologie des Rhinoskleroms. Journal: Wiener Medizinische Wochenschrift; vol. 32, pp. 969–972.