Diagnosis is made by clinical observation and the following tests.

(1) Gram stain of the fluid from pustules or bullae, and tissue swab.

(2) Blood culture

(3) Urine culture

(4) Skin biopsy

(5) Tissue culture

Magnetic resonance imaging can be done in case of ecthyma gangrenosum of plantar foot to differentiate from necrotizing fasciitis.

The main organism associated with ecthyma gangrenosum is "Pseudomonas aeruginosa". However, multi-bacterial cases are reported as well. Prevention measures include practicing proper hygiene, educating the immunocompromised patients for awareness to avoid possible conditions and seek timely medical treatment.

Often a diagnosis of exclusion, skin biopsy shows a neutrophillic inflammatory infiltrate.

First-line therapy for disseminated or localized instances of pyoderma gangrenosum is systemic treatment by corticosteroids and ciclosporin. Topical application of clobetasol, mupirocin, and gentamicin alternated with tacrolimus can be effective.

Pyoderma gangrenosum ulcers demonstrate pathergy, that is, a worsening in response to minor trauma or surgical debridement. Significant care should be taken with dressing changes to prevent potentially rapid wound growth. Many patients respond differently to different types of treatment, for example some benefit from a moist environment, so treatment should be carefully evaluated at each stage.

Papules that begin as small "spouts" can be treated with Dakins Solution to prevent infection and wound clusters also benefit from this disinfectant. Wet to dry applications of Dakins can defeat spread of interior infection. Heavy drainage can be offset with Coban dressings. Grafting is not recommended due to tissue necrosis.

If ineffective, alternative therapeutic procedures include systemic treatment with corticosteroids and mycophenolate mofetil; mycophenolate mofetil and ciclosporin; tacrolimus; thalidomide; infliximab; or plasmapheresis.

There is currently a phase III trial for the use of the IL-1B modulating agent gevokizumab in treating the ulcers of pyoderma gangrenosum.

Other conditions that can result in symptoms similar to the common form include contact dermatitis, herpes simplex virus, discoid lupus, and scabies.

Other conditions that can result in symptoms similar to the blistering form include other bullous skin diseases, burns, and necrotizing fasciitis.

Clinical features along with the familial tendency may be enough to make a diagnosis. Genetic testing may also be used.

Impetigo is usually diagnosed based on its appearance. It generally appears as honey-colored scabs formed from dried serum, and is often found on the arms, legs, or face. If a visual diagnosis is unclear a culture may be done to test for resistant bacteria.

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 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.

Pyoderma means any skin disease that is pyogenic (has pus). These include superficial bacterial infections such as impetigo, impetigo contagiosa, ecthyma, folliculitis, Bockhart's impetigo, furuncle, carbuncle, tropical ulcer, etc. Autoimmune conditions include pyoderma gangrenosum. Pyoderma affects more than 111 million children worldwide, making it one of the three most common skin disorders in children along with scabies and tinea.

Grover's may be suspected by its appearance, but since it has such a characteristic appearance under the microscope a shave skin or punch biopsy is often performed.

The current ‘best’ practice in the UK is to treat the underlying venous reflux once an ulcer has healed. It is questionable as to whether endovenous treatment should be offered before ulcer healing, as current evidence would not support this approach as standard care. EVRA (Early Venous Reflux Ablation) ulcer trial - A UK NIHR HTA funded randomised clinical trial to compare early versus delayed endovenous treatment of superficial venous reflux in patients with chronic venous ulceration opened for recruitment in October 2013. The study hopes to show an increase in healing rates from 60% to 75% at 24 weeks.

Research from the University of Surrey and funded by the Leg Ulcer Charity is currently looking at the psychological impact of having a leg ulcer, on the relatives and friends of the affected person, and the influence of treatment.

A clinical severity score has been developed to assess chronic venous ulcers. It is based on the CEAP (clinical, etiology, anatomy, and pathophysiology) classification system developed by an expert panel. A high score gives a poor prognosis.

Acne treatment may require oral tetracycline antibiotics or isotretinoin. Treatments directed at tumor necrosis factor (TNF) (infliximab, etanercept) and interleukin-1 (anakinra) have shown a good response in resistant arthritis and pyoderma gangrenosum. Other traditional immunosuppressant treatments for arthritis or pyoderma gangrenosum may also be used.

Suggested diagnostic criteria for cryoglobulinemic disease fall into the following obligatory and additional categories:

- Obligatory criteria: 1) cold sensitivity; 2) cutaneous symptoms (i.e. urticaria, purpura, Raynaud phenomenon, ulceration/necrosis/gangrene, and/or livedo reticularis); 3) arterial and/or venous thrombotic events; fever; 4) arthralgia/myalgia; 5) neuritis in >1 site; and 6) renal disorder.

- Additional criteria: 1) typical biopsy findings at site(s) of involvement and 2) angiogram evidence of occlusion in one or more small to medium sized arteries.

The diagnosis of secondary cryofibrinogenemia also requires evidence for the cited infectious, malignant, premalignant vasculitis, and autoimmune disorders while the diagnosis of primary cryofibriongenemia requires a lack of evidence for 1) the cited associated disorders, 2) other vascular occlusive diseases, and 3) cryoglobulinemia.

Success in treating the primary disease has been reported using blood clot lysing agents such as anabolic steroids (e.g. danazol or stanozolol which is no longer available in the USA), streptokinase, and streptodornase; anticoagulants such as heparin and warfarin, and immunosuppressive drug regimens such as a corticosteroid (e.g. prednisone) combined with either azathioprine of chlorambucil. Very moderate cases may do well by simply avoiding cold exposure. Treatment with a corticosteroid plus low-dose aspirin followed by maintenance therapy with an anabolic steroid where necessary are recommended for moderately severe cases. Very severe cases generally require an immunosuppressive drug regimen and if extreme or life threatening require resorting to plasmaphoresis or plasma exchange. Cryofiltration apheresis, a method to remove plasma agents by removing cold-induced precipitated material, may be an effective alternative to plasmaphoresis and plasma exchange but is still regarded as second-line therapy for cryofibirnogenemic disease treatment.

During the several years following its initial diagnosis, some 27-47% of primary cryofibrinoginemic diseases are complicated by the development of a B-cell or T-cell lymphoma. That is, the cryofibrinoginemic disease may appear to precede by years the malignant disorder to which it is associated. Accordingly, patients require careful follow-up not only to treat their primary cryofibrinoginemic disease but also to monitor them for movement to the diagnosis of secondary cryofibrinoginemic disease caused by the development of one of these hematological malignancies.

CRMO/CNO is a diagnosis of exclusion. This means that other diseases must be ruled out before the diagnosis can be made. Generally, many tests are required, such as blood tests, x-rays, bone scans, MRI and often a bone biopsy.

Ecthyma is a variation of impetigo, presenting at a deeper level of tissue.

It is usually associated with Group A (beta-hemolytic) Streptococcus (abbreviated GAS).

Sweating causes lesions to form, but lesions aggravated by sweat usually return to "normal" fairly quicklyavoiding sweat is not a reason to avoid exercise. Minor outbreaks can be controlled with prescription strength topical cortisone creams. More severe eruptions usually clear up after treatment for one to three months with Accutane or tetracycline. If these fail or the outbreak is severe, PUVA phototherapy treatments, antifungal pills and cortisone injections are alternatives.

Some research has suggested a correlation of Grover's disease with mercury toxicity in which case Dimercaptosuccinic acid might help.

Many conditions mimic or may be mistaken for warfarin necrosis, including pyoderma gangrenosum or necrotizing fasciitis. Warfarin necrosis is also different from another drug eruption associated with warfarin, purple toe syndrome, which usually occurs three to eight weeks after the start of anticoagulation therapy. No report has described this disorder in the immediate postpartum period in patients with protein S deficiency.

Many conditions affect the human integumentary system—the organ system covering the entire surface of the body and composed of skin, hair, nails, and related muscle and glands. The major function of this system is as a barrier against the external environment. The skin weighs an average of four kilograms, covers an area of two square meters, and is made of three distinct layers: the epidermis, dermis, and subcutaneous tissue. The two main types of human skin are: glabrous skin, the hairless skin on the palms and soles (also referred to as the "palmoplantar" surfaces), and hair-bearing skin. Within the latter type, the hairs occur in structures called pilosebaceous units, each with hair follicle, sebaceous gland, and associated arrector pili muscle. In the embryo, the epidermis, hair, and glands form from the ectoderm, which is chemically influenced by the underlying mesoderm that forms the dermis and subcutaneous tissues.

The epidermis is the most superficial layer of skin, a squamous epithelium with several strata: the stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum basale. Nourishment is provided to these layers by diffusion from the dermis, since the epidermis is without direct blood supply. The epidermis contains four cell types: keratinocytes, melanocytes, Langerhans cells, and Merkel cells. Of these, keratinocytes are the major component, constituting roughly 95 percent of the epidermis. This stratified squamous epithelium is maintained by cell division within the stratum basale, in which differentiating cells slowly displace outwards through the stratum spinosum to the stratum corneum, where cells are continually shed from the surface. In normal skin, the rate of production equals the rate of loss; about two weeks are needed for a cell to migrate from the basal cell layer to the top of the granular cell layer, and an additional two weeks to cross the stratum corneum.

The dermis is the layer of skin between the epidermis and subcutaneous tissue, and comprises two sections, the papillary dermis and the reticular dermis. The superficial papillary dermis with the overlying rete ridges of the epidermis, between which the two layers interact through the basement membrane zone. Structural components of the dermis are collagen, elastic fibers, and ground substance. Within these components are the pilosebaceous units, arrector pili muscles, and the eccrine and apocrine glands. The dermis contains two vascular networks that run parallel to the skin surface—one superficial and one deep plexus—which are connected by vertical communicating vessels. The function of blood vessels within the dermis is fourfold: to supply nutrition, to regulate temperature, to modulate inflammation, and to participate in wound healing.

The subcutaneous tissue is a layer of fat between the dermis and underlying fascia. This tissue may be further divided into two components, the actual fatty layer, or panniculus adiposus, and a deeper vestigial layer of muscle, the panniculus carnosus. The main cellular component of this tissue is the adipocyte, or fat cell. The structure of this tissue is composed of septal (i.e. linear strands) and lobular compartments, which differ in microscopic appearance. Functionally, the subcutaneous fat insulates the body, absorbs trauma, and serves as a reserve energy source.

Conditions of the human integumentary system constitute a broad spectrum of diseases, also known as dermatoses, as well as many nonpathologic states (like, in certain circumstances, melanonychia and racquet nails). While only a small number of skin diseases account for most visits to the physician, thousands of skin conditions have been described. Classification of these conditions often presents many nosological challenges, since underlying etiologies and pathogenetics are often not known. Therefore, most current textbooks present a classification based on location (for example, conditions of the mucous membrane), morphology (chronic blistering conditions), etiology (skin conditions resulting from physical factors), and so on. Clinically, the diagnosis of any particular skin condition is made by gathering pertinent information regarding the presenting skin lesion(s), including the location (such as arms, head, legs), symptoms (pruritus, pain), duration (acute or chronic), arrangement (solitary, generalized, annular, linear), morphology (macules, papules, vesicles), and color (red, blue, brown, black, white, yellow). Diagnosis of many conditions often also requires a skin biopsy which yields histologic information that can be correlated with the clinical presentation and any laboratory data.

Progressive vaccinia (also known as "Vaccinia gangrenosum," and "Vaccinia necrosum") is a rare cutaneous condition caused by the vaccinia virus, characterized by painless, but progressive, necrosis and ulceration.

The first element of treatment is usually to discontinue the offending drug, although there have been reports describing how the eruption evolved little after it had established in spite of continuing the medication. Vitamin K1 can be used to reverse the effects of warfarin, and heparin or its low molecular weight heparin (LMWH) can be used in an attempt to prevent further clotting. None of these suggested therapies have been studied in clinical trials.

Heparin and LMWH act by a different mechanism than warfarin, so these drugs can also be used to prevent clotting during the first few days of warfarin therapy and thus prevent warfarin necrosis (this is called 'bridging').

Based on the assumption that low levels of protein C are involved in the underlying mechanism, common treatments in this setting include fresh frozen plasma or pure activated protein C.

Since the clot-promoting effects of starting administration of 4-hydroxycoumarins are transitory, patients with protein C deficiency or previous warfarin necrosis can still be restarted on these drugs if appropriate measures are taken. These include gradual increase starting from low doses and supplemental administration of protein C (pure or from fresh frozen plasma).

The necrotic skin areas are treated as in other conditions, sometimes healing spontaneously with or without scarring, sometimes going on to require surgical debridement or skin grafting.

Prognosis will depend on your child's individual disease and response to treatment. It is best to discuss the prognosis with your child's pediatric rheumatologist.

All patients with symptomatic cryoglobulinemia are advised to avoid, or protect their extremities, from exposure to cold temperatures. Refrigerators, freezers, and air-conditioning represent dangers of such exposure.