Disease Characteristics

IgA-mediated Neutrophil-directed Skin Diseases

Severe COVID-19 Infection with Lung Tissue Injuries

Circulating IgA

Skin-specific IgA are detected in linear IgA dermatosis and IgA pemphigus.

Early immunoglobulin surge is IgA, rather than IgM.

IgA: IgM ratios markedly increase compared to milder cases.

IgA levels parallel disease severity.

COVID-19-specific IgA levels significantly correlate with disease severity.

Tissue-bound IgA

Skin tissue IgA deposits are detected in linear IgA dermatosis, IgA pemphigus, and dermatitis herpetiformis.

IgA-vasculitis (with IgA deposited in blood vessels) occurred in some COVID-19 patients.

IgA-nephropathy (with IgA deposited in kidney) occurred in some COVID-19 patients.

Both dimeric IgA and monomeric IgA against SARS-CoV-2 in respiratory mucosa alveola were detected in severe COVID patients.

Neutrophil Tissue Infiltration

Neutrophil infiltration in skin is detected in linear IgA dermatosis, IgA pemphigus, and dermatitis herpetiformis.

Neutrophil infiltration in lung tissues is primarily detected in severe cases.

Neutrophils adhered to alveola epithelial cells were found in autopsy of COVID patients.

Response to dapsone treatment

Responses are good to excellent.

Rapid resolution of skin diseases can be achieved as early as one to three days.

A small study of 44 ICU-admitted severe COVID-19 patients documented 100% survival (22/22) of patients treated with dapsone, compared to 36% mortality (8/22) of patients who were not treated.

Leprosy patients infected by COVID-19 while on dapsone treatment did not become severely ill and recovered.