<h1>Panaritium</h1>

A panaritium is an acute or chronic infection of the finger or toe, it can superficial, deep or located around the nail. The cause of infection can be either bacteria or fungi, the germs create a cavity in which  pus is collected. Left untreated panaritium either open to the skin and eliminate pus (fistulizing) or extend into the deep tissue.

Germs associated with panaritium development

Panaritium is most commonly associated with  Staphylococcus aureus which is found in 50 % of cases, producing a creamy, thick and odorless pus. Other germs that can be isolated from the lesion are:

1. Streptococcus which produces a seropurulent secretion 
2. Anaerbic germs that produce a greyish, malodorous (fetid) pus. For example Bacteroides and Anaerobic streptococci 
3. Gram-negative germs which can be either aerobic (Pseudomonas) or anaerobic (Escherichia coli, Enterobacter) 

In 30% of cases there are associations of the above mentioned germs and even fungi (Candida) or viruses (Herpes).

How does panaritium evolve?

Most often the infection is produce as a consequence of trauma which leads to the inoculation of the germs followed by their multiplication. Rarely there can be a haematogenous inoculation, in which germs are carried through the blood vessels from another infection site in the organism.
The germs release a series of enzymes, as well as endo- and exotoxins. These products of the bacterial metabolism stimulate the mononuclear phagocyte system of the organism leading to an inflammatory reaction at the site of inoculation. This is the congestive phase of the infection, which is catheterized by the developing of edema.
Edema leads to an increased pressure pressure in the tissue, leading to stagnation of blood in the venous circulation and thus favoring the development of microtrombosis. The result is ischemia of the tissue which in time will lead to necrosis and development of an abscess, this is known as the suppurative phase. The abscess is a cavity with sclerous walls that constitute a barrier between the healthy tissues and the destroyed ones Clinically in this phase there is a pulsating pain and fluctuance.
Anatomical spaces of the fingers and hand allow propagation of the infection which can affect tendons, synovial membranes, articulations and bones. Also the infection can extend to the forearm leading to lymphangitis, adenitis and even septicemia. This is also called the elimination phase due to the fact that a tegumentary fistula can  form through which sphaceli resulted from the tissue necrosis is eliminated.
The last phase is the cicatrization phase characterized by healing with or without sequelae depending on how fast and fair the treatment have been applied.

Causes of panaritium?

1. Trauma followed by infection: inadequate cleaning of the wound, without debridement of the necrotic tissues, inefficient draining.
2. Minor lesions of the skin: excoriations, stings, manicure, bite wounds, piodermitis, eczema, dermatitis
3. Thermal or chemical burns, which can get infected
4. Contusion lesions that are considered infected from the beginning  

Diffusion of the infection is favored by:

1. The anatomy of the respective region, characterized by structures that are poor in blood  vessels (tendons, articulations) or are rich in terminal blood vessels (fingertip) which favor infection
2. Poor  hygiene of the tegument when the aggression takes place 
3.  Associated diseasses 

• Diabetes, corticotherapy, immunosuppressive drugs which favor infection extension and delay regeneration
• Blood diseases that lead to a decreased immunity
• cancer determines a loos of the organism resistance to infection and delays repair of the lesion

Panaritum classification

• Depending on the location of the lesion there are:

1.  Distal panaritium -  the anterior surface of the distal phalanx
2. Middle panaritium - the anterior surface of the middle phalanx
3. Proximal panaritium - the anterior surface of the proximal phalanx
4. Posterior panaritum - on the posterior surface of the above mentioned segments

•  Dependng on the deepness of the lesion there are:

1.  Superficial panaritia  that involves only the epidermis and dermis. There are multiple forms: erythematous panaritum, flictenular panaritum, anthracoid panaritum. Also in this category are the infections that involve the lateral surface of the nail (paronychia), root of the nail (eponychia) and the surface underneath the nail (subonychia)
2. Subcutaneous panaritium that invlovesthe subcutaneous tissue of the finger. In this category are the  panaritia that affect the pulp of the proximal and middle phalanx. As a complication the infection can extend underneath and affect the synovial sheath of the tendons (tenosynovitis), the bones (osteitis) and joints (arthritis)