Primary diagnosis usually starts off with a thorough physical exam and evaluation of medical history. To further investigate, a dermoscope, a diagnostic tool, is used by the dermatologist to examine the skin using a magnified lens. A complete blood count (CBC) along with other blood tests can also be done to rule out any sort of other infections. Lastly, a skin biopsy test may be ordered to arrive at a definitive diagnosis. This pathological examination of the skin biopsy helps to arrive at the correct diagnosis via a fungal culture(mycology). The biopsy is put together with clinical and microscope findings and study of the special tissues if need be. The signs and symptoms of MG are similar to many other clinical conditions and therefore it is necessary to perform all of the additional tests in order for a physician to correctly rule out all other possible diagnoses.

The exact cause of Majocchi's granuloma is not well established however a dysfunctinoal immune system may be a causative factor. The first form of MG, the superficial perifollicular form occurs predominately on the legs of otherwise healthy young women who repeatedly shave their legs and develop hair follicle occlusions that directly or indirectly disrupt the follicle and allow for passive introduction of the organism into the dermis. Hence, the physical barrier of the skin is important because it prevents the penetration of microorganisms. Physical factors that play a major role in inhibiting dermal invasion include the interaction among keratin production, the rate of epidermal turnover, the degree of hydration and lipid composition of the stratum corneum, CO levels, and the presence or absence of hair. Keratin and/or necrotic material can also be introduced into the dermis with an infectious organism to further enhance the problem. In immunocompromised individuals, the use of topical corticosteroids may lead to a dermatophyte infection due to local immunosuppression.

Granuloma annulare, microscopically, consists of dermal epithelioid histiocytes around a central zone of mucin - a so-called palisaded granuloma.

Because granuloma annulare is usually asymptomatic and self-limiting with a course of about 2 years, initial treatment is generally topical steroid creams, followed by oral steroids and finally intradermal injections at the site of each ring. Treatment success varies widely, with most patients finding only brief success with the above-mentioned treatments. New research out of India suggests that the combination of rifampin (600 mg), ofloxacin (400 mg), and minocycline hydrochloride (100 mg) once monthly, or ROM therapy, produces promising results. Most lesions of granuloma annulare disappear in pre-pubertal patients with no treatment within two years while older patients (50+) have rings for upwards of 20 years. The appearance of new rings years later is not uncommon.

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.

The basis of management is to find and correct the underlying cause. Many times cats with EGC will respond to treatment with corticosteroids or to ciclosporin.

Localized granuloma annulare has a tendency towards spontaneous resolution. Localized lesions have been treated with potent topical corticosteroids.

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.

Patch-type granuloma annulare (also known as "Macular granuloma annulare") is a skin condition of unknown cause, more commonly affecting women between 30 and 70 years of age, characterized by flat or slightly palpable erythematous or red-brown skin lesions.

Annular elastolytic giant-cell granuloma (also known as "Giant cell elastophagocytosis," "Meischer's granuloma," "Miescher's granuloma of the face") is a cutaneous condition characterized histologically by a dermal infiltrate of macrophages.

1)positive tuberclin test

2)chest radiograph

3)CT scan

4)cytology/biopsy (FNAC)

5)AFB staining

6)mycobacterial culture

Actinic granuloma (also known as "O'Brien granuloma") is a cutaneous condition characterized histologically by a dermal infiltrate of macrophages.

Actinic granuloma is an asymptomatic granulomatous reaction that affects sun-exposed skin, most commonly on the face, neck, and scalp.

It is characterized by annular or polycyclic lesions that slowly expand centrifugally and have an erythematous elevated edge and a hypopigmented, atrophic center.

Advise to reduce exposure to the sun and to use sunscreen.

Treatment with topical halometasone cream, pimecrolimus cream.

Perforating granuloma annulare is a skin condition of unknown cause, usually appearing on the dorsal hands, presenting as papules with a central keratotic core.

NL is diagnosed by a skin biopsy, demonstrating superficial and deep perivascular and interstitial mixed inflammatory cell infiltrate (including lymphocytes, plasma cells, mononucleated and multinucleated histiocytes, and eosinophils) in the dermis and subcutis, as well as necrotising vasculitis with adjacent necrobiosis and necrosis of adnexal structures. Areas of necrobiosis are often more extensive and less well defined than in granuloma annulare. Presence of lipid in necrobiotic areas may be demonstrated by Sudan stains. Cholesterol clefts, fibrin, and mucin may also be present in areas of necrobiosis. Depending on the severity of the necrobiosis, certain cell types may be more predominant. When a lesion is in its early stages, neutrophils may be present, whereas in later stages of development lymphocytes and histiocytes may be more predominant.

Granuloma annulare in HIV disease is a skin condition characterized typically by papular and generalized skin lesions.

Generalized granuloma annulare is a skin condition of unknown cause, tending to affect women in the fifth and sixth decades, presenting as a diffuse but symmetrical, papular or annular eruption of more than ten skin lesions, and often hundreds.

Sarcoidosis may be divided into the following types:

- Annular sarcoidosis

- Erythrodermic sarcoidosis

- Ichthyosiform sarcoidosis

- Hypopigmented sarcoidosis

- Löfgren syndrome

- Lupus pernio

- Morpheaform sarcoidosis

- Mucosal sarcoidosis

- Neurosarcoidosis

- Papular sarcoid

- Scar sarcoid

- Subcutaneous sarcoidosis

- Systemic sarcoidosis

- Ulcerative sarcoidosis

Diagnosis of sarcoidosis is a matter of exclusion, as there is no specific test for the condition. To exclude sarcoidosis in a case presenting with pulmonary symptoms might involve a chest radiograph, CT scan of chest, PET scan, CT-guided biopsy, mediastinoscopy, open lung biopsy, bronchoscopy with biopsy, endobronchial ultrasound, and endoscopic ultrasound with fine-needle aspiration of mediastinal lymph nodes (EBUS FNA). Tissue from biopsy of lymph nodes is subjected to both flow cytometry to rule out cancer and special stains (acid fast bacilli stain and Gömöri methenamine silver stain) to rule out microorganisms and fungi.

Serum markers of sarcoidosis, include: serum amyloid A, soluble interleukin-2 receptor, lysozyme, angiotensin converting enzyme, and the glycoprotein KL-6. Angiotensin-converting enzyme blood levels are used in the monitoring of sarcoidosis. A bronchoalveolar lavage can show an elevated (of at least 3.5) CD4/CD8 T cell ratio, which is indicative (but not proof) of pulmonary sarcoidosis. In at least one study the induced sputum ratio of CD4/CD8 and level of TNF was correlated to those in the lavage fluid. A sarcoidosis-like lung disease called granulomatous–lymphocytic interstitial lung disease can be seen in patients with common variable immunodeficiency (CVID) and therefore serum antibody levels should be measured to exclude CVID.

Differential diagnosis includes metastatic disease, lymphoma, septic emboli, rheumatoid nodules, granulomatosis with polyangiitis, varicella infection, tuberculosis, and atypical infections, such as "Mycobacterium avium" complex, cytomegalovirus, and cryptococcus. Sarcoidosis is confused most commonly with neoplastic diseases, such as lymphoma, or with disorders characterized also by a mononuclear cell granulomatous inflammatory process, such as the mycobacterial and fungal disorders.

Chest radiograph changes are divided into four stages:

1. bihilar lymphadenopathy

2. bihilar lymphadenopathy and reticulonodular infiltrates

3. bilateral pulmonary infiltrates

4. fibrocystic sarcoidosis typically with upward hilar retraction, cystic and bullous changes

Although people with stage 1 radiographs tend to have the acute or subacute, reversible form of the disease, those with stages 2 and 3 often have the chronic, progressive disease; these patterns do not represent consecutive "stages" of sarcoidosis. Thus, except for epidemiologic purposes, this categorization is mostly of historic interest.

In sarcoidosis presenting in the Caucasian population, hilar adenopathy and erythema nodosum are the most common initial symptoms. In this population, a biopsy of the gastrocnemius muscle is a useful tool in correctly diagnosing the person. The presence of a noncaseating epithelioid granuloma in a gastrocnemius specimen is definitive evidence of sarcoidosis, as other tuberculoid and fungal diseases extremely rarely present histologically in this muscle.

Subcutaneous granuloma annulare (also known as "Deep granuloma annulare," and "Pseudorheumatoid nodule") is a skin condition of unknown cause, most commonly affecting children, with girls affected twice as commonly as boys, characterized by skin lesions most often on the lower legs.

Treatment usually involves surgical removal of the lesion down to the bone. If there are any adjacent teeth, they are cleaned thoroughly with scaling and root planing (SRP) to remove any possible source of irritation. Recurrence is around 10%.

The granulomas of tuberculosis tend to contain necrosis ("caseating tubercules"), but non-necrotizing granulomas may also be present. Multinucleated giant cells with nuclei arranged like a horseshoe (Langhans giant cell) and foreign body giant cells are often present, but are not specific for tuberculosis. A definitive diagnosis of tuberculosis requires identification of the causative organism by microbiologic cultures.

There is no clearly defined cure for necrobiosis. NLD may be treated with PUVA therapy and improved therapeutic control.

Although there are some techniques that can be used to diminish the signs of necrobiosis such as low dose aspirin orally, a steroid cream or injection into the affected area, this process may be effective for only a small percentage of those treated.

Aspiration pneumonia is typically caused by aspiration of bacteria from the oral cavity into the lungs, and does not result in the formation of granulomas. However, granulomas may form when food particles or other particulate substances like pill fragments are aspirated into the lungs. Patients typically aspirate food because they have esophageal, gastric or neurologic problems. Intake of drugs that depress neurologic function may also lead to aspiration. The resultant granulomas are typically found around the airways (bronchioles) and are often accompanied by foreign-body-type multinucleated giant cells, acute inflammation or organizing pneumonia. The finding of food particles in lung biopsies is diagnostic.

Eosinophilic granuloma is a form of Langerhans cell histiocytosis. It is a condition of both human and veterinary pathology. Colloquially, the reaction pattern is sometimes referred to as a rodent ulcer.

Feline eosinophilic granuloma complex is synonymous with "feline eosinophilic skin diseases". This is considered to be a cutaneous reaction pattern that can be the manifestation of a number of underlying infections, allergies or ectoparasite infestations. It can also be idiopathic, that is have no known underlying trigger. The eosinophilic reaction is common in feline inflammatory disease and the eosinophilic granuloma can be a hereditary reaction pattern in some lines of domestic cats.

The diagnosis is made clinically, and usually this is clear cut if the lesion is associated with the flange of a denture. Tissue biopsy is not usually indicated before removal of the lesion, since the excises surgical specimen is usually sent for histopathologic examination and the diagnosis is confirmed retrospectively. Rarely, incisional biopsy may be indicated to rule out neoplasia, e.g. in the presence of suspicious ulceration. The appearance may also be confused with pyogenic granuloma.

The excessive tissue is composed of cellular, inflamed fibrous connective tissue. The appearance of an epulis fissuratum microscopically is an overgrowth of cells from the fibrous connective tissue. The epithelial cells are usually hyperkeratotic and irregular, hyperplastic rete ridges are often seen.