Pestilence-like eczematoid dermatitis (Dermatitis Eczematoides Infectiosa) is a localized acute eczematoid dermatitis that develops on the basis of an infected sexually transmitted disease lesion. It gradually spreads to nearby areas, often forming patches that eliminate dampness and crust over, or it may dry out and flake.

bubble_chart Etiology

The patient initially has a localized staphylococcal infection, which then spreads from the infected site to nearby areas. This process is not only an autoinoculation but also a manifestation of autosensitization. The sources of infection can include otitis media, boils, carbuncles, eye, ear, or vaginal discharge, wound infections, as well as chronic ulcers and burn infections. The surrounding skin may develop an allergic reaction to the bacteria or other products from the infected site's exudate or to the damaged tissue, leading to the occurrence of eczema-like dermatitis.

bubble_chart Clinical Manifestations

Before the rash appears, there is a chronic suppurative infection. The primary lesion may be a blister or pustule, an inflamed papule with scales or crusts, or a red spot that eliminates dampness, often occurring symmetrically on exposed areas. Sometimes, the earliest lesions are ruptured abscesses, boils, carbuncles, sinusitis, chronic otitis media, bedsores, fistulas, scabies, or ulcers, or they may be focal infections in the nose, eyes, or vagina. Often, when the local lesion worsens, the skin around the infection site develops erythema, papules, blisters, pustules, and crusts, gradually spreading outward to form patches of eczematous dermatitis oozing seropurulent fluid, with crusting on the surface. When symptoms are mild or inflammation subsides, the affected area becomes dry and desquamates. In severe cases, the affected area may swell, erode, exude fluid, and exhibit pronounced peripheral erythema, papules, small vesicles, pustules, and other acute eczematous changes, forming irregularly bordered patches of eczematous skin lesions. Local lymph nodes are often swollen, and occasionally, there may be a rise in body temperature. Generalized dermatitis may also occur elsewhere on the body due to an auto-sensitivity reaction. Some patients may develop linear or streak-like eczematous dermatitis due to scratching, with asymmetrical rashes and intense cutaneous pruritus, though generally milder than eczema.

The pathological changes of this disease include hypertrophy and edema of the epidermal prickle cell layer, with superficial areas prone to erosion, often containing staphylococci. The dermal papillary layer shows edema, congestion, and inflammatory cell infiltration. Laboratory tests reveal an increase in neutrophils.

bubble_chart Diagnosis

The disease is characterized by acute eczema-like lesions such as erosion, blisters, and pustules occurring on the surrounding skin based on an infected lesion, making diagnosis straightforward. However, it must be differentiated from contact dermatitis, eczema, impetigo, and seborrheic dermatitis.

bubble_chart Treatment Measures

First, use antibiotics to eliminate the primary infection site. An antibiotic sensitivity test can be conducted to select the appropriate sensitive antibiotics. Corticosteroids such as prednisone and dexamethasone can be used to rapidly alleviate severe acute inflammation and discontinue unsuitable topical medications. For acute dampness-eliminating conditions, apply wet compresses with a 1:5000 to 1:8000 potassium permanganate solution or a 1:20 compound aluminum sulfate solution (Burow's solution). When exudation decreases, use topical 1% gentian violet solution, gentamicin solution, lotion, or emulsion. For chronic dermatitis with minimal exudation, apply 10% ichthammol ointment, mupirocin ointment, or erythromycin and chloramphenicol ointments.