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Neutrophilic Dermatoses - Causes, Symptoms, Diagnosis, and Treatment

Published on Jan 24, 2023 and last reviewed on Feb 02, 2023   -  8 min read


It is a group of inflammatory skin disorders characterized by lesions infiltrated with inflammatory cells (neutrophils). Read the article for more details.


The term "neutrophilic dermatoses" are a category of diseases defined by skin lesions. The condition has significant epidermal, dermal, or hypodermal infiltrate, predominantly of neutrophils. It is without signs of infection or genuine vasculitis (inflammation of blood vessels). Neutrophilic dermatoses frequently develop near an injury site, such as an insect bite, needle prick, or biopsy. Koebner phenomenon, often known as the isomorphic response, is the name of this response to damage. Assessing clinical and pathologic aspects and identifying related disorders are the basis for classifying neutrophilic dermatoses.

What Are the Conditions Included in Neutrophilic Dermatoses?

Skin disorders termed neutrophilic dermatoses are as follows:

  • Acute febrile neutrophilic dermatosis (Sweet syndrome).

  • Pyoderma gangrenosum.

  • Erythema elevatum diutinum.

  • Behcet disease.

  • Bowel bypass syndrome (bowel-associated dermatitis-arthritis syndrome).

  • Neutrophilic urticarial dermatosis.

The above diseases falling under the category of neutrophilic dermatoses are demonstrated individually in association with their causes, symptoms, diagnosis, and treatment.

What Is Acute Febrile Neutrophilic Dermatosis?

Fever, inflamed or blistering skin lesions, and mucosal lesions are the marks of this unusual skin disorder known as acute febrile neutrophilic dermatosis. It is also known as Sweet syndrome or disease, after Plymouth, England-based physician Dr. Robert Douglas Sweet initially reported it in 1964.


Acute febrile neutrophilic dermatosis has no recognized specific etiology. However, the following factors may cause acute febrile neutrophilic dermatosis:

  • Solar exposure.

  • Infection of the upper respiratory tract (chest infection, streptococcal throat infection).

  • Bowel diseases (ulcerative colitis or Crohn's disease).

  • Internal cancer typically of the genitourinary system, breast, or bowel.

  • Pregnancy.

  • Digestive tract infection (campylobacter).

  • Vaccination.


Acute febrile neutrophilic dermatosis might manifest only once or repeatedly. However, some or all of the symptoms listed below describe it:


Acute febrile neutrophilic dermatosis can be diagnosed clinically. However, it can occasionally be challenging to distinguish it from inflammatory disorders like vasculitis or infections like chickenpox. Skin biopsy typically confirms the diagnosis. The removal of a sample of skin is known as a skin biopsy. A local anesthetic injection into the skin is generally used to numb the area. The injection temporarily hurts. A suture or dressing may cover the biopsy site after the surgery.


Symptoms of acute febrile neutrophilic dermatosis typically improve soon after treatment. Systemic steroids, including Prednisolone, are usually recommended in 30- to 60 mg daily doses. The fever, skin rashes, and other symptoms disappear in a few days. Lower corticosteroid doses are frequently needed for a few weeks to months to avoid relapse.

What Is Pyoderma Gangrenosum?

Pyoderma gangrenosum (PG) manifests as a painful, quickly expanding ulcer.

Its defining features are pathergy (the formation or flare of skin lesions after minor trauma) and a full-thickness ulcer with blue/purple undermined borders.


  • Pyoderma gangrenosum is an autoinflammatory condition (increased response to an internal antigen) brought on by a malfunctioning neutrophil, including cytokines and T cells. A hereditary tendency might exist.

  • Drugs, including Cocaine, Isotretinoin, Propylthiouracil, and Sunitinib, are occasionally linked to pyoderma gangrenosum.

  • Skin damage is a frequent trigger (the pathergy reaction), and surgical triggers are well-known and frequently mistaken for wound infections.


  • It may begin as a tiny pimple, a red bump, or a blood blister frequently mistaken for an insect bite.

  • An ulcer results from subsequent skin breakdown. The ulcer may quickly deepen and enlarge.

  • The ulcer's edge typically has a purple color and is weakened.

  • Pyoderma gangrenosum typically causes excruciating discomfort.

  • Ulcers can appear all at once or over months to years.


Pyoderma gangrenosum can be identified by its distinctive look and excruciating discomfort. Sometimes a biopsy may be required. When receiving treatment, the neutrophilic inflammatory infiltrates produced by Pyoderma gangrenosum disappear.


Pyoderma gangrenosum is primarily treated non-surgically. Minor ulcers are frequently managed using the following:

  • Potent topical steroid cream.

  • Tacrolimus cream.

  • Injections of intralesional steroid into the ulcer edge.

  • Oral medicines that reduce inflammation, such as Doxycycline and Minocycline.

What Is Erythema Elevatum Diutinum (EED)?

An erythema elevatum diutinum (EED) is a rare necrotizing vasculitis. It presents as red, purple, brown, or yellow papules (raised spot), plaques or nodules on the buttocks, and other extensor surfaces above joints and the back of the hands.


EED falls under the category of small vessel vasculitis. Although the exact cause of EED is still unknown, the following conditions have been linked to it:

  • Recurring bacterial infections (especially streptococci).

  • Viral infections (including hepatitis B and HIV).

  • Hematological disorders (involving blood).

  • Rheumatological situations (involving joints, Muscles, tendons, and ligaments).

Clinical Features

  • Usually, lesions on the backs of the hands begin as papules or nodules.

  • The elbows, wrists, ankles, fingers, and toes are other extensor surfaces impacted. Susceptible areas include the palms, soles, forearms, legs, and trunk.

  • Most lesions have symmetrical appearances.

  • Lesions gradually change from yellow to pinkish to red, purple, or brown.

  • Lesions may grow during the day before shrinking to their original size at night.

  • Blisters and ulcers can seldom develop.

  • Over the underlying tissue, lesions typically feel solid and easily moveable.

  • EED can induce a burning or itchy feeling in addition to being painful or symptomless.

  • After being exposed to cold, symptoms may worsen.


A skin biopsy is the most crucial test to confirm an EED diagnosis.


  • The disease progression can be slowed down by medication.

  • The quick start of the action and positive clinical results has resulted in Dapsone being regarded as the medication of choice for EED. However, the ceasing of medicine results in the lesions recurring.

  • Niacinamide, Colchicine, and other medications have also occasionally been observed to be efficient.

What Is Behcet Disease?

Recurrent, excruciating oral and genital ulcers, a wide range of skin lesions, and eye issues characterize a rare, multi-system disorder called Behcet disease (BD). The intestines, brain system, lungs, and arteries are just a few other affected organs. Although it can affect all arteries and veins of all diameters, it is a type of vasculitis that usually affects tiny arteries.


Although the cause of Behç et disease is uncertain, it is believed to be autoimmune. Numerous genetic variables, in particular HLA-B51, are linked to it. Several illnesses, including Streptococcus sanguis, herpes simplex, hepatitis viruses, and parvovirus B19, have also been identified as potential triggers.

Clinical Features

  • Oral ulcers in the mouth, pharynx, and tonsils characterize them. They range in size from 1 - 3 cm. They can be extensive. A fibrin-coated base and a yellow pseudomembrane are present.

  • Painful genital ulcers. Recurrent ulcers in the vulva, vagina, perineum, groin, scrotum, and penis. Genital sores can leave scars after healing and are less frequent than oral lesions.


Behcet disease does not have a definitive diagnostic test. Typical investigations comprise the following tests:

  • Complete blood count.

  • Electrolytes and urea.

  • Serology for syphilis.

  • Anti-nuclear substance.

  • To rule out HSV infection, culture/PCR from oral or genital ulcers.

  • Skin biopsy.


Treatment for Behç et illness should be individualized for each patient based on clinical signs and disease severity. Treatments for Behç et disease should focus on reducing any inflammatory flare-ups and preventing irreparable organ damage, especially in the early stages of the illness. The condition typically progresses in a relapsing-remitting manner. Topical treatment includes the following.

  • Corticosteroids as mouthwash, gel, or cream.

  • Pimecrolimus as an alternative to topical steroids.

  • Antibiotics such as tetracyclines.

  • Chlorhexidine mouthwash is an example of an antiseptic.

  • Diclofenac.

  • Lidocaine.

What Is Neutrophilic Urticarial Dermatosis?

Lesions caused by neutrophilic urticarial dermatosis have a histological response pattern that shows neutrophils stacked up between collagen fibers.

  • The skin lesions may be accompanied by fever and arthritis.

  • Raised ESR/CRP and neutrophil leukocytosis (increased white cell count) are found during blood testing.

  • Rheumatoid arthritis and other underlying inflammatory diseases are frequently present.

  • Unlike acute neutrophilic dermatosis (Sweet disease), this condition does not involve the mucosal membranes.

What Is Bowel Bypass Syndrome?

Rash and arthritis characterize bowel bypass syndrome. The most frequent cause is bowel shortening surgery, in which a 'blind loop' of the bowel is formed. In the past, this surgery was frequently used to treat morbid obesity. Bowel bypass syndrome can occur in up to 20% of people having bowel bypass surgery.


  • It is considered that bacterial overgrowth in a blind loop of the colon causes bowel bypass syndrome. A blind loop is a section of the small intestine that does not allow the passage of digested food. It results in the shortening of the small intestine, which decreases fat absorption and causes weight reduction.

  • Bacterial antigens are released into the bloodstream due to overgrowth in the blind loop. These antigens are called peptidoglycans. Peptidoglycans interact with circulating antibodies to form antibody-antigen complexes, which are then deposited in the skin and joints and cause inflammation.

  • Bowel bypass syndrome has been associated with certain bacteria, which includes Escherichia coli, Bacteroides fragilis, and, Streptococcus species.


  • Symptoms appear after one to six years of bowel bypass surgery.

  • Typically lasting two to four weeks. Symptoms can return every four to six weeks.

  • Skin lesions appear on the trunk and upper arms; little red pimples (papules), blisters, and bumps appear.


  • Skin biopsy is the main diagnostic procedure.

  • Upon skin biopsies, early lesions may show perivascular neutrophil granules and dilated dermal arteries.

  • Neutrophil infiltration, prominent dermal edema, and dermo-epidermal separation are signs of more advanced lesions.


  • Bowel bypass syndrome is treated surgically by removing the blind loop or revoking the bowel bypass.

  • Systemic corticosteroids are not curative, although short courses benefit symptoms.

  • Antibiotics are also advantageous. Efficient regimes include Minocycline, Erythromycin, Clindamycin, Sulfamethoxazole, Trimethoprim, and Metronidazole.


Neutrophilic dermatoses have a variety of cutaneous and extracutaneous symptoms. Infectious, inflammatory, neoplastic, and drug-related conditions are common underlying associations. Dermatologists should be consulted when symptoms resemble this condition.

Article Resources

Last reviewed at:
02 Feb 2023  -  8 min read




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