Tuberculosis cutis miliaris disseminata: causes, symptoms, diagnosis, and treatment

Tuberculosis cutis miliaris disseminata is a manifestation of miliary tuberculosis in the skin.


Causes

Tuberculosis cutis miliaris disseminata is a rare and severe tuberculosis infection due to acute hematogenous dissemination, more common in children, and can occur when resistance is reduced after measles or other eruptions. Patients are often accompanied by visceral tuberculosis such as military pulmonary tuberculosis and lymphatic tuberculosis.


Signs and Symptoms

The clinical manifestations are pinhead sized, generalized, pale red or dark red papules, vesicles, pustules, or hemorrhagic lesions. Some papules can develop into lupomas. The vesicles can be necrotic, forming ulcers, and mycobacterium tuberculosis can be found in the secretions. The ulcers are covered by crusts, often in severe patients. Erythema nodosum is sometimes visible.

Infants and children are mainly invaded, but also in adult patients with severe immunosuppression, such as AIDS patients. The original infected focus can be hidden. Positive results in acid-fast bacilli test with skin biopsy suggest tuberculosis infection in the body. The results in tuberculin test are negative in the early stage and may be positive in the late stage. Patients present systemic symptoms such as fever.


Histopathology

In the early stage, non-specific inflammation is the manifestation. Neutrophil infiltration, small blood vessel inflammation, embolism, and necrosis, and some mycobacterium tuberculosis in the dermis can be seen. In the late stage, tuberculous granulomas can be seen in the lesion.


Diagnosis

This disease should be considered if generalized eruptive papules occur in severe patients with tuberculosis or exposed to tuberculosis. Definitive diagnosis can be provided by bacterial culture in the secretion or skin lesion biopsy.


Treatment

First-line anti-tuberculosis drugs include isoniazid (INH), rifampicin (RIF), pyrazinamide (PZA), and ethambutol (EMB). These drugs should be treated in combination.

Second-line anti-tuberculosis drugs are often used in drug-resistant tuberculosis patients or patients unable to tolerate first-line drugs, mainly including aminoglycosides and fluoroquinolones, such as streptomycin, kanamycin, amikacin, capreomycin, levofloxacin, and moxifloxacin. Aminoglycosides are only for parenteral use.

Other second-line drugs include ethionamide, cycloserine, and para-aminosalicylic acid, with anti-tuberculosis effect weaker than first-line drugs, with strong toxicity, but effective against drug-resistant tuberculosis.

Bedaquiline, delamanid, and sutezolid are new anti-tuberculosis drugs and are usually reserved for extensively drug-resistant tuberculosis, or patients unable to tolerate other second-line drugs.