The patient presented with a swollen and slightly red left upper arm, initially treated as erysipelas. Two hours later the swelling involved the lateral breast wall, the pectoral and the deltoid muscle. Ultrasound excluded thrombosis. The patient became confuse with decreasing blood pressure. Blisters appeared and a CT was performed.
At the initial ultrasound examination diffuse subcutaneous oedema and areas of hypoechoic, oedematous muscle tissue was seen (Fig. 1).
An unenhanced CT (due to low GFR) showed axillary oedema with enlarged lymph nodes, severe subcutaneous swelling and thickened muscles on the left upper arm. The lateral breast was involved as well as the rotator cuff, the triceps-, biceps-, deltoid-, trapezoid- and the pectoral muscles. Also a slight thickening of the left sternocleid muscle was noted.
3 small (1-2 mm) air bubbles were detected close to the left humeroscapular joint and in the subscapular muscle (Fig. 2-4). One air bubble (1 mm) was present in the left sternocleid muscle. No iv-injection or blood testing had been performed at the left arm. Based on the rapid progression of symptoms and the detection of even a minimal air development, the patient was suspected having necrotising fasciitis and underwent acute surgery.
Necrotising fasciitis (NF) is a rare (4 in 100.000 persons/year) but serious, progressive and rapidly spreading infection localised in the profound fascia with secondary necrosis of muscles and subcutaneous tissue. NF is caused by infection with Grp. A Haemolytic Streptococcus, sometimes in combination with other aerobe or anaerobe bacteria species such as Bacteroides spp., Clostridium Perfringens, Peptostreptococcus spp., Enterobacteriaceae, Proteus spp., Klebsiella spp. and Pseudomonas Aeruginosa. Also fungal infections can lead to NF. The bacteria spreads haematogenic (e.g. from a joint infection), from the surface following trauma or from viscera after surgery [1]. Still a large number of cases are idiopathic. Insulin dependent diabetes, alcoholism, drug abuse, overweight and suppression of the immune system, seem to be predisposing factors. NF carries a high mortality rate (25-50%) and therefore determining the diagnosis with no delay followed by correct treatment is essential and lifesaving [2].
The patient typically presents with a swollen, painful, red extremity [3]. Often antibiotic treatment has been given prior to attendance but with no effect. The swelling may progress rapidly (within hours) and haemorrhagic blisters on the swollen skin may appear. The patients temperature is often elevated and signs of infection may be seen in the blood tests. If the right treatment is not given initially, the clinical situation may progress into pre-shock, confusion and, eventually, death [4, 5].
In the present case, the patient had no predisposing morbidity. Venous thrombosis was excluded. Due to the rapid progression of the clinical symptoms combined with the few tissue air bubbles detected at the CT-examination, acute surgery with complete opening of the rotator cuff and debridement was performed. The patient received hyper bar oxygen treatment, recovered after a few weeks and underwent reconstructive surgery with a good result. The infection had spread from the left shoulder joint and only Grp. A Haemolytic Streptococcus was found.
This case is interesting, since only a few air bubbles were present in the tissue. The majority of cases published demonstrate a large amount of free air, which really makes the diagnosis very easy. The radiologist needs to remember, that even though a gas producing bacteria, such as Clostridium Perfringens, is not present, air may still be detected in the tissue due to the CO2 production following fermentation and the rapid necrosis. Therefore the presence of even a single air bubble strongly supports the diagnosis of NF and surgical action must be instantly initiated.
Necrotising faciitis
The patient is a 63-year-old male. Based on the provided CT and ultrasound images, there is significant swelling in the subcutaneous and deep soft tissue regions of the left upper arm, accompanied by areas of low density and a small amount of gas bubbles, suggesting possible gas formation within the soft tissues. Furthermore, the swelling has extended to the lateral chest wall, the pectoralis major muscle, and the fascial intervals of the deltoid muscle. Ultrasound images also show disordered echoes in the subcutaneous and deeper tissues, without a distinct large abscess cavity but with a suspicious fluid area. Overall, the imaging findings indicate involvement of the deep fascia and adjacent soft tissues, with a small amount of gas formation.
Taking into account the patient’s advanced age; the rapidly progressing swelling of the left upper arm and lateral chest wall; skin blisters, redness, and the presence of gas shadows; acute confusion (changes in mental status); and hypotension, along with imaging findings showing small amounts of gas in the fascia and deep tissues, the most likely diagnosis is Necrotizing Fasciitis. Pathogen testing indicating Group A Hemolytic Streptococcus infection further supports this conclusion. Once confirmed, urgent management is necessary to prevent further soft tissue necrosis and systemic complications.
During the acute phase or early postoperative period, the patient should primarily rest, avoid tension on the wound, and prevent secondary infections. Once the infection is controlled and the patient enters the rehabilitation phase, gradual exercise can be introduced, provided the wound is healing and the patient’s condition is stable:
Throughout the rehabilitation process, adherence to the FITT-VP principles (Frequency, Intensity, Time, Type, Progression) is essential. Reassess recovery and tolerance weekly or biweekly to adjust the exercise plan accordingly. If any significant pain, swelling, or other discomfort occurs, discontinue the exercises and seek medical evaluation.
This report is based solely on the provided medical history and imaging data for preliminary analysis and should not replace in-person evaluation and professional medical advice. The patient’s definitive treatment and rehabilitation plan must be determined in conjunction with a face-to-face assessment by a specialist physician, taking into account the patient’s clinical condition.
Necrotising faciitis
