In all cases of suspected NEH, a skin biopsy should be performed, because the clinical symptoms are non specific, but the histopathological findings on the biopsy are specific. The biopsy shows characteristic changes of the eccrine glands, the major sweat glands of the body.

In NEH, eccrine gland necrosis, and neutrophils surroundings the eccrine glands, are typical findings on biopsy. If the chemotherapy has recently been administered, chemotherapy induced neutropenia may be present, and, as a result, the neutrophils may be absent. But the other characteristic finding, i.e. eccrine gland necrosis, can still be seen. A vacuolar interface dermatitis also is visible in glands and ducts, along with necrosis of the lining cells.

In addition, in patients receiving chemotherapy, keratinocyte atypia can be seen.

Erythema nodosum is diagnosed clinically. A biopsy can be taken and examined microscopically to confirm an uncertain diagnosis. Microscopic examination usually reveals a neutrophilic infiltrate surrounding capillaries that results in septal thickening, with fibrotic changes in the fat around blood vessels. A characteristic microscopic finding is radial granulomas, well-defined nodular aggregates of histiocytes surrounding a stellate cleft.

Additional evaluation should be performed to determine the underlying cause of erythema nodosum. This may include a full blood count, erythrocyte sedimentation rate (ESR), antistreptolysin-O (ASO) titer and throat culture, urinalysis, intradermal tuberculin test, and a chest x-ray. The ESR is typically high, the C-reactive protein elevated, and the blood showing an increase in white blood cells.

The ESR is initially very high, and falls as the nodules of erythema nodosum. The ASO titer is high in cases associated with a streptococcal throat infection. A chest X-ray should be performed to rule out pulmonary diseases, in particular sarcoidosis and Löfgren syndrome.

Diagnosis is clinical, based on observation. Biopsy is rarely required.

Due to its overwhelming incidence on the gingiva, the condition is often associated with two other diseases, though not because they occur together. Instead, the three are associated with each other because they appear frequently on gingiva—peripheral giant cell granuloma and peripheral ossifying fibroma. Detailed analysis can be used to distinguish these conditions.

Neutrophilic lobular panniculitis is a cutaneous condition characterized by inflammation of the subcutaneous fat.

A single case report suggested that oral dapsone may be useful for prevention. However, the efficacy of oral dapsone as prevention has not been demonstrated very clearly until now.

Differentiation between this and SCC would be based on a history of recent trauma or dental treatment in the area.

Immunohistochemistry may aid the diagnosis. If the lesion is NS, there will be focal to absent immunoreactivity for p53, low immunoreactivity for MIB1 (Ki-67), and the presence of 4A4/p63- and calponin-positive myoepithelial cells.

Prognosis is usually good, however recurrence may happen with rate up to 16%. Presence of myxoid structures in the pyogenic granuloma may be the main cause of recurrence.

Although pyogenic granulomas are not infectious or malignant, treatment may be considered because of bleeding or ulceration. Frequently, pyogenic granulomas are treated with electrodesiccation (cauterization) and curettage (excision), though laser treatment using pulsed dye laser or CO laser is often effective.

Several reports have demonstrated the efficacy of topical application of the beta-adrenergic antagonist timolol in the treatment of pediatric pyogenic granuloma.

There is usually no treatment if the pyogenic granuloma occurs during pregnancy since the lesion may heal spontaneously. Recurrent bleeding in either oral or nasal lesions may necessitate excision and cauterization sooner, however. If aesthetics are a concern, then treatment may be pursued as well. Usually, only minor surgery may be needed, along with a dental cleaning for oral lesions to remove any calculus or other source of irritation. For nasal lesions, nose-picking should be discouraged.

Studies show a moderate neutrophilia (less than 50%), elevated ESR (greater than 30 mm/h) (90%), and a slight increase in alkaline phosphatase (83%). Skin biopsy shows a papillary and mid-dermal mixed infiltrate of polymorphonuclear leukocytes with nuclear fragmentation and histiocytic cells. The infiltrate is predominantly perivascular with endothelial-cell swelling in some vessels, but vasculitic changes (blood clots; deposition of fibrin, complement, or immunoglobulins within the vessel walls; red blood cell extravasation;inflammatory infiltration of vascular walls) are absent in early lesions.

Perivasculitis occurs secondarily, because of cytokines released by the lesional neutrophils. True transmural vasculitis is not an expected finding histopathologically in SS.

The management of lipodermatosclerosis may include treating venous insufficiency with leg elevation and elastic compression stockings; in some difficult cases, the condition may be improved with the additional use of the fibrinolytic agent, stanozol. Fibrinolytic agents use an enzymatic action to help dissolve blood clots.

Stanozol is injected directly into the affected area, Venous Ablation has also been known to help circulation in patients.

The clinical differential diagnosis includes pyoderma gangrenosum, infection, erythema multiforme, adverse drug reactions, and urticaria. Recurrences are common and affect up to one third of patients.

Alpha-1 antitrypsin deficiency panniculitis is a panniculitis associated with a deficiency of the α-antitrypsin enzyme.

Erythema nodosum is the most common form of panniculitis. It is most common in the ages of 20–30, and affects women 3–6 times more than men.

About 15 percent of patients with inflammatory bowel disease develop erythema nodosum.

Erythema nodosum is a form of panniculitis characterised by tender red nodules, 1–10 cm, associated with systemic symptoms including fever, malaise, and joint pain. Nodules may become bluish-purple, yellowing, and green, and subside over a period of 2–6 weeks without ulcerating or scarring. Erythema nodosum is associated with infections, including Hepatitis C, EBV and tuberculosis, Crohn's disease and sarcoidosis, pregnancy, medications including sulfonamides, and some cancers, including Non-Hodgkin lymphoma and pancreatic cancer.

Septal panniculitis is a condition of the subcutaneous fat affecting the layer of adipose tissue that lies between the dermis and underlying fascia, of which there are two forms: acute erythema nodosum and chronic erythema nodosum.

Healing is prolonged, and usually takes 6–10 weeks. The ulcer heals by secondary intention.

Pemphigus is a group of autoimmune blistering diseases that may be classified into the following types:

Verruciform xanthoma is uncommon, with a female:male ratio of 1:1.1

Pemphigus defines a group of autoimmune interepithelial blistering diseases that are characterized by loss of normal cell-cell adhesion (acantholysis), and by the presence of pathogenic (predominantly IgG) autoantibodies reacting against epithelial adhesion molecules. Pemphigus is further divided in two major subtypes: pemphigus vulgaris (PV) and pemphigus foliaceus (PF). However, several other disorders such as IgA pemphigus, IgE pemphigus, pemphigus herpetiformis, drug induced pemphigus, Senear Usher syndrome and endemic pemphigus foliaceus exist;recognized by a dermatologist from the appearance and distribution of the skin lesions. It is also commonly diagnosed by specialists practicing otolaryngology- head and neck surgery, periodontists, oral and maxillofacial surgeons and eye doctors, as lesions can affect the eyes and mucous membrane of the oral cavity. Intraorally it resembles the more common diseases lichen planus and mucous membrane pemphigoid. Definitive diagnosis requires examination of a skin or mucous membrane biopsy by a dermatopathologist or oral pathologist. The skin biopsy is taken from the edge of a blister, prepared for histopathology and examined with a microscope. The pathologist looks for an intraepidermal vesicle caused by the breaking apart of epidermal cells (acantholysis). Thus, the superficial (upper) portion of the epidermis sloughs off, leaving the bottom layer of cells on the "floor" of the blister. This bottom layer of cells is said to have a "tombstone appearance".

Definitive diagnosis also requires the demonstration of anti-desmoglein autoantibodies by direct immunofluorescence on the skin biopsy. These antibodies appear as IgG deposits along the desmosomes between epidermal cells, a pattern reminiscent of chicken wire. Anti-desmoglein antibodies can also be detected in a blood sample using the ELISA technique.

Treatment protocol is not well established. Some sources report that approximately half of the patients will fully recover after lengthy (mean time 14.5 months, range 2–24 months) expectant management.

Treatment with steroids is lengthy and usually requires about 6 months. While some source report very good success with steroids most report a considerable risk of recurrence after a treatment with steroids alone. Steroids are known to cause elevation of prolactin levels and increase risk of several conditions such as diabetes, and other endocrinopathies which in turn increase the risk of IGM. Treatment with topical steroids to limit side effects was also reported in one case. For surgical treatment recurrence rates of 5-50% have been reported.

A 1997 literature review article recommended complete resection or corticosteroid therapy, stating also that long-term follow-up was indicated due to a high rate of recurrence.

Treatment with a combination of glucocorticoids and prolactin lowering medications such as bromocriptine or cabergoline was used with good success in Germany. Prolactin lowering medication has also been reported to reduce the risk of recurrence. In cases of drug-induced hyperprolactinemia (such as antipsychotics) prolactin-sparing medication can be tried.

Methotrexate alone or in combination with steroids has been used with good success. Its principal mechanism of action is immunomodulating activity, with a side effect profile that is more favorable for treating IGM.

Colchicine, azathioprine and NSAIDs have also been used.

The majority (90%) of cases have not had detectable cytogenetic abnormalities. Most importantly, the Philadelphia chromosome and other BCR/ABL fusion genes are not detected.

Verruciform xanthoma is most likely not a human papillomavirus associated lesion and the foam cells in the lesions are most likely derived from the monocyte—macrophage lineage. More research is needed is determine the cause.

Weber–Christian disease, also known as relapsing febrile nodular nonsuppurative panniculitis, is a cutaneous condition characterized by recurrent subcutaneous nodules that heal with depression of the overlying skin.

It is type of panniculitis.

It is a rare disease seen in females 30–60 years of age. It is a recurring inflammation of fatty layers of tissue present beneath the skin. Clinical course is characterised by exacerbations and remissions. Lesions are bilaterally symmetrical and are usually seen in the lower legs.

The diagnosis is made in a patient with history of significant alcohol intake who develops worsening liver function tests, including elevated bilirubin and aminotransferases. The ratio of aspartate aminotransferase to alanine aminotransferase is usually 2 or more. In most cases, the liver enzymes do not exceed 500. The changes on liver biopsy are important in confirming a clinical diagnosis.

Atrophic connective tissue panniculitis is a rare condition, and often occurs on the upper or lower extremities.