- Erysipela is a type of cellulitis, but must be diferenciated because of the complications
- In diabetic foot, the best treatment is Ampicilline-Sulbactam plus Clindamicine
- Skin biopsy lacks of sensibility, but must be performed
- In clinical practice, it is very important to follow the rapid progressive cellulitis (e.g. pen mark), to determinate the progression and do diferencial diagnosis with necrotizing fascitis.
Cellulitis is an acute, spreading pyogenic inflammation of the dermis and subcutaneous
tissue, usually complicating a wound, ulcer, or dermatosis. The area, usually on the
leg, is tender, warm, erythematous, and swollen. It lacks sharp demarcation from uninvolved
skin. Erysipelas is a superficial cellulitis with prominent lymphatic involvement,
presenting with an indurated, “peau d’orange” appearance with a raised border
that is demarcated from normal skin. The distinctive features, including the anatomical
location of cellulitis and the patient’s medical and exposure history, should guide
appropriate antibiotic therapy
Crepitant cellulitis is produced by either clostridia or non–spore-forming anaerobes (bacteroides species, peptostreptococci, and peptococci) — either alone or mixed with facultative bacteria, particularly Escherichia coli, klebsiella, and aeromonas. Gangrenous cellulitis produces necrosis of the subcutaneous tissues and overlying skin. Skin necrosis may complicate conventional cellulitis or may occur with distinctive clinical features (including necrotizing cutaneous mucormycosis in immunocompromised patients
Specific pathogens are suggested when infection follows exposure to seawater ( Vibrio vulnificus ), fresh water ( Aeromonas hydrophila ), or quacultured fish ( Streptococcus iniae)
Occasionally, cellulitis may be caused by the spread of subjacent osteomyelitis. Rarely, infection may emerge as apparent cellulitis, sometimes distant from the initial site. Crepitant cellulitis on the left thigh, for instance, might be a manifestation of a colonic diverticular abscess.
Cellulitis infrequently occurs as a result of bacteremia. Uncommonly, pneumococcal cellulitis occurs on the face or limbs in patients with diabetes mellitus, alcohol abuse, systemic lupus erythematosus, the nephrotic syndrome, or a hematologic cancer.Meningococcal cellulitis occurs rarely, although it can affect both children (periorbital cellulitis) and adults (cellulitis on an extremity). 11 Bacteremic cellulitis due to V. vulnificus with prominent hemorrhagic bullae may follow the ingestion of raw oysters by patients with cirrhosis, hemochromatosis.
Cellulitis caused by other gram-negative organisms (e.g., E. coli ) usually occurs through a cutaneous source in an immunocompromised patient but can also develop through
Bacteremia 14 ; it sometimes follows Pseudomonas aeruginosa bacteremia in patients with neutropenia. In immunocompromised persons, less common opportunistic pathogens (e.g.,
Helicobacter cinaedi in patients with human immunodeficiency virus infection; Cryptococcus neoformans; and fusarium, proteus, and pseudomonas species) have also been associated
with bloodborne cellulitis.
However, data from five series using needle aspiration have elucidated common pathogens.
Among 284 patients, a likely pathogen was identified in 29 percent. Gram-positive microorganisms (mainly Staphylococcus aureus, group A or B streptococci, viridans streptococci, and Enterococcus faecalis ) accounted for 79 percent of cases.
A small study in children demonstrated higher yields when needle aspirates were obtained from the point of maximal inflammation than when they were obtained from the leading edge.
These data indicate that antimicrobial therapy for cellulitis in immunocompetent hosts should be focused primarily on gram-positive cocci.
Broader coverage is warranted in patients with diabetes. Among 96 leg-threatening foot infections (including cellulitis) in patients with diabetes, the main potential pathogens recovered from deep wounds or débrided tissue were gram-positive aerobes including S. aureus,
enterococci, and streptococci (in 56 percent of cases); gram-negative aerobes including proteus, E. coli, klebsiella, enterobacter, acinetobacter, and P. aeruginosa (in 22 percent);
and anaerobes including bacteroides and peptococcus (in 22 percent). 31
USUAL CELLULITIS TREATMENT
SPECIFIC CELLULITIS TREATMENT
This broad range of microorganisms should also be considered as potential pathogens in cellulitis that occurs as a complication of decubitus ulcers. Bacteremia is uncommon in cellulitis: among 272 patients, initial blood cultures were positive in 4 percent
In contrast, blood cultures are indicated in patients who have cellulitis superimposed on lymphedema.. attributable to the preexisting lymphedema and the infecting bacterial species. Blood cultures are also warranted in patients with buccal or periorbital cellulitis, in patients in whom a salt-water or fresh-water source of infection is likely (Table 3), and in patients with chills and high fever, which suggest bacteremia.
study involving 17 patients with suspected necrotizing fasciitis, 11 cases were ultimately confirmed to be necrotizing fasciitis (at surgery or, in 1 case, on autopsy), and 6 were confirmed to be cellulitis on the basis of the clinical course 33
; on MRI, all 11 cases of necrotizing fasciitis were identified (100 percent sensitivity), but 1 of the 6 cases of cellulitis was misdiagnosed (for a specificity of 86 percent). The criteria for identifying necrotizing fasciitis on MRI include the involvement of deep fasciae, as evidenced
by fluid collection, thickening, and enhancement with contrast material.
But ultrasonography can be helpful in detecting the subcutaneous accumulation of pus as a complication of cellulitis and can aid in guiding aspiration.
Diabetic foot infections involve multiple potential pathogens, and broad antimicrobial coverage
is required.
31
Ampicillin–sulbactam and imipenem– cilastatin were shown in a randomized, double-blind trial to have similar cure rates in this setting (81 percent vs. 85 percent), but the former combination was more cost effective. randomized, double-blind trial of treatment of complicated skin and soft-tissue infections in 819 hospitalized adults,
42
44 percent of whom had cellulitis. The cure rates were 89 percent for linezolid and 86 percent for oxacillin. Clinically relevant pathogens isolated from contiguous sites included S. aureus
(in 35 percent), group A streptococci (in 11 percent), and group B streptococci (in 27 percent),
but infections due to methicillin-resistant S. aureus were excluded. A trial comparing linezolid and vancomycin in the treatment of adults with methicillin- resistant S. aureus infections, including 175 skin and soft-tissue infections, found similar cure rates (79 percent with linezolid and 73 percent with vancomycin), but cellulitis accounted for only 13 percent of these infections.
ancillary measures
The local care of cellulitis involves the elevation and immobilization of the involved limb to reduce swelling and cool sterile saline dressings to remove purulence from any open lesion. Interdigital dermatophytic infections should be treated with a topical antifungal agent until they have been cleared. Such lesions may provide ingress for infecting bacteria.
Several classes of topical antifungal agents are effective in clearing up fungal infection when
applied one to two times daily; these include imidazoles (clotrimazole and miconazole), allylamines (terbinafine), and substituted pyridones (ciclopirox olamine).
44
Observational data suggest that after the successful treatment of such dermatophytic infections,
the subsequent prompt use of topical antifungal agents at the earliest evidence of recurrence
(or prophylactic application once or twice Patients with peripheral edema are predisposed
Reference
Cellulitis
No hay comentarios:
Publicar un comentario