Dermatology - Cellulitis

Dermatology - Cellulitis
Cellulitis is a rapid and expanding infection that affects the skin and underlying tissues. The point of entry is typically evident, and Staphylococcus aureus is the predominant pathogen.
Erysipelas is a form of cellulitis that affects the lymphatic system of the skin. It is typically caused by beta-hemolytic streptococci bacteria. prevalent pathogens in chronic soft tissue infections include Nocardia spp, Sporothrix schenckii, Madurella spp, Scedosporium spp, and nontuberculous mycobacteria. In cases of dog or cat bites, prevalent pathogens are Pasteurella spp and Capnocytophaga canimorsus.
Risk factors encompass host defense deficiencies, diabetes mellitus, substance and alcohol misuse, malignancy and cancer treatment, persistent lymphedema, and prior occurrences of cellulitis/erysipelas.

The onset of fever and chills may occur swiftly, preceding the clinical manifestation of cellulitis. Elevated body temperature (38.5°C) and shivering commonly linked to group A streptococcal infection. Lymph nodes might exhibit regional enlargement and tenderness.

A crimson, scorching, swollen, lustrous patch that starts at the point of entry expands with movement towards the center and has clearly defined edges that are uneven and somewhat raised. Plaque can lead to the formation of vesicles, bullae, erosions, abscesses, bleeding, and necrosis. The lesions exhibit tenderness and cause pain.

The diagnosis is mostly made through clinical assessment of the appearance of the lesion and the patient's medical history. Confirmation through culture is performed when necessary. To confirm the presence of necrotizing fasciitis, it is recommended to do a deep biopsy and frozen section histology. The differential diagnosis comprises deep vein thrombophlebitis, early contact dermatitis, urticaria, insect bite, fixed drug eruption, erythema nodosum, acute gout, and erythema migrans. If necrosis is observed, it is advisable to investigate the possibility of vascular disease, calciphylaxis, warfarin-induced necrosis, traumatic damage, cryoglobulinemia, fixed drug eruption, pyoderma gangrenosum, and brown recluse spider bite.

Cellulitis should be treated with high-dose antibiotics based on the specific type of bacteria that is suspected or proven through culture, taking into consideration its sensitivity.