Lichen scrofulosorum caused by Mycobacterium szulgai: a new cause of a tuberculide reaction

Tuberculids: A Narrative Review

Tuberculids are a group of dermatoses with tuberculoid histology and the absence of tubercle bacilli. They are considered to be hypersensitivity reactions to circulating Mycobacterium tuberculosis (M. tb) or its antigens in individuals with good immunity. The objective of the review is to provide a detailed literature review of all available articles on tuberculids in the past 10 years and provide an update on epidemiology, etiopathogenetic mechanisms, clinical manifestations, and treatment. A search was performed on PubMed using the keywords lichen scrofulosorum, papulonecrotic tuberculid, erythema induratum, and erythema nodosum tuberculosis for all articles, with no restrictions on age, gender, or nationalities. An update on tuberculids, including some new concepts in pathogenesis, atypical presentations, new investigative modalities, and treatments are reviewed.

Cutaneous Mycobacterium szulgai infection in a patient with Cushing's syndrome: a case report and literature review

BACKGROUND

Opportunistic infection is an under-recognized complication of Cushing's syndrome, with infection due to atypical mycobacterium rarely reported. Mycobacterium szulgai commonly presents as pulmonary infection, with cutaneous infection seldom reported in the literature.

CASE PRESENTATION

48-year-old man with a newly-diagnosed Cushing's syndrome secondary to adrenal adenoma presented with a subcutaneous mass on the dorsum of his right hand, was diagnosed with cutaneous Mycobacterium szulgai infection. The most likely source of the infection was through minor unnoticed trauma and inoculation from a foreign body. The patient's Cushing's syndrome, high serum cortisol levels and secondary immune suppression facilitated mycobacterial replication and infection. The patient was successfully treated with adrenalectomy, surgical debridement of cutaneous lesion, and a combination of rifampicin, levofloxacin, clarithromycin, and ethambutol for 6 months. There were no signs of relapse one year after cessation of anti-mycobacterial treatment. A literature review on cutaneous M. szulgai infection to further characterize the clinical characteristics of this condition, identified 17 cases of cutaneous M. szulgai infection in the English literature. Cutaneous M. szulgai infections with subsequent disease dissemination are commonly reported in immunocompromised hosts (10/17, 58.8%), as well as in immunocompetent patients with a history of breached skin integrity, such as invasive medical procedures or trauma. The right upper extremity is the most commonly involved site. Cutaneous M. szulgai infection is well controlled with a combination of anti-mycobacterial therapy and surgical debridement. Disseminated infections required a longer duration of therapy than localized cutaneous infections. Surgical debridement may shorten the duration of antibiotics.

CONCLUSIONS

Cutaneous M. szulgai infection is a rare complication of adrenal Cushing's syndrome. Further studies are needed to provide evidence-based guidelines on the best combination of anti-mycobacterial and surgical therapy for managing this rare infective complication.

Psoriasiform type of lichen scrofulosorum: clue to disseminated tuberculosis

We present a 16-year-old girl with tuberculosis of the lungs, lymph nodes, and liver, who had extensive inflammatory lesions with pustules, which resembled psoriasis. A skin biopsy showed extensive tuberculoid granulomas surrounding hair follicles, consistent with lichen scrofulosorum. Antitubercular therapy led to resolution of skin lesions. This severe inflammatory type of lichen scrofulosorum is extremely rare.