What is an Acute Febrile Neutrophilic Dermatosis?
It is defined as a disorder in which there is an association with the hematologic diseases which includes the leukemia and immunologic disease which can be rheumatoid arthritis and inflammatory bowel disease. There has been a genetic association with it. It is also known as the sweet syndrome. It is a skin disease in which there is a sudden onset of fever, leucocytosis and formation of tender and erythematous papules. These are well demarcated and show an intense infiltration of neutrophils granulocytes when examined histo pathologically. It was sweet who was working in the Plymouth in the year 1964. He described the disease with the following features such as fever, leucocytosis, acute tender red papules and a papillary dermal infiltrate of neutrophils. It leads to the name acute febrile neutrophilic dermatosis. Fever and neutrophilia are not common features. The diagnosis is based on the typical eruption pattern and the histological features.
What are the signs and symptoms of Acute febrile neutrophilic dermatosis ?
It includes the acute, tender, erythematous plaques, nodes, pseudo vesicles and blisters with annular or arciform pattern. It occurs on the legs, neck, head and arms. It may occur on the back of hand and fingers. It rarely involves the trunk. There is a occurrence of the fever in 50 percent of the cases. Arthritis or arthralgia is seen in the 60 percent of the cases. An eye involvement with the conjunctivitis is seen in the 38 percent of the cases it is followed by the oral apthae. The differential diagnosis includes the erythema multiform, erythema nodosum and adverse drug reactions with the urticaria. The recurrence is quite common and involves the 33 percent of the patients.
What is the etiology of Acute febrile neutrophilic dermatosis ?
It is classified depending on the clinical setting. It can be classical, idiopathic, malignancy associated or drug induced SS. In the case of systemic diseases it is a reactive phenomena and a cutaneous marker. There is a need of systemic evaluation. It occurs when the cutaneous lesions are severe and the hematological values are not normal. One fifth of the cases are associated with the malignancy. They are mainly hematological and include mainly the acute myelogenous leukemia. In half of the cases there is an underlying condition. The hematological diagnosis is preceded by the attacks of SS. It is diagnosed from 3 months to 6 years and may lead to the evaluation of the patient in the idiopathic group. There are many studies which suggest that the treatment with the hematopoietic growth facts including the granulocyte colony stimulating factor which is used to treat the AML and granulocyte macrophage colony stimulating can cause SS. The lesions occur when the patient develops leucocytosis and neutrophilia but not when the patient is neutropenic. The G CSF may lead to SS in neutropenic patients due to the induction of stem cell proliferation along with the differentiation of neutrophils and the prolongation of neutrophil survival.
What are the systemic diseases associated with the Acute febrile neutrophilic dermatosis ?
The differential diagnosis includes the erythema multiform, erythema nodosum and adverse drug reactions with the urticaria. The recurrence is quite common and involves the 33 percent of the patients.
What are the laboratory studies of Acute febrile neutrophilic dermatosis ?
There are different studies which show the moderate neutrophilia in less than 50 percent of the cases. There is an elevated ESR seen in the 90 percent of the cases. It is more than 30 mm per hour. One can also observe the increase in alkaline phosphate levels. On the biopsy of skin one can observe the papillary and mid dermal mixed infiltrates of PMN leucocytes along with the nuclear fragmentation and histiocytic cells. The infiltrate is peri vascular and there is an endothelial swelling seen in some vessels. One cannot observe the vasculitis change seen in the early lesions. It is secondary to the noxious products released from neutrophils. The blood vessels which are present for long duration are more likely to develop vasculitis than of the short duration and it is due to the presence of more exposure to noxious metabolites. So, vasculitis does not exclude the diagnosis of SS.
What is the treatment of Acute febrile neutrophilic dermatosis ?
It includes the use of systemic corticosteroids with the use of prednisone from 0.5 to 1.5 mg per kg of body weight per day. It produces a great improvement and is the gold standard treatment for treatment. It improves he temperature, WBC count and eruption within 3 days. The skin lesions clear within 3 to 9 days. The laboratory values return to normal. They may recur also. The dose of corticosteroids is decreased to zero within 2 to 6 weeks. The resolution of eruption is followed by the scar formation. The disease clears spontaneously and the use of topical or intra lesional cortico steroids is effective as a mono therapy. The rapid resolution occurs by oral potassium iodide or colchicine. The patients which have systemic infection or in those in which the cortico steroids are not given can use potassium iodide as a first line treatment. In one study indomethacin was given at 150 mg per day for one week and 100 mg per day was given for 2 more weeks. Most of the patients respond well with the attenuation of fever and athralgia in 48 hrs. The eruptions took 1 to 2 weeks to clear. The patients with continues cutaneous lesions were treated successfully with the prednisolone at 1mg per kg per day. When the indomethacin was discontinued no relapse was seen. There are other drugs which can be given in the place of steroids like doxycycline, clofazimine, dapsone and cyclosporine. All these drugs affect the functioning of neutrophils.