Spongiosis or a spongiotic reaction pattern is the histological hallmark of intercellular epidermal edema, viewed as clear spaces within the epidermis. Although considered a histopathological term, spongiosis has clinical correlations, with the variable degrees of spongiotic reaction leading to different dermatological findings. This review aimed to highlight the spongiotic reactive patterns found in different autoimmune bullous dermatoses, considering the paucity of publications in this domain. The pathogenesis of spongiosis assumes the passage of extravasated edema fluid from the dermis into the epidermis, frequently accompanied by dermal inflammatory cells, and classification of the spongiotic reaction patterns, as well as their associated spongiotic dermatitis, take into consideration the type and distribution of these inflammatory cells. It is mandatory to consider different reactive processes, specific for other skin disorders, which act as simulants of different spongiotic patterns for the diagnosis. Considering the possible transient occurrence, the heterogeneity and non-specificity of the histopathological features of these diseases, the diagnosis is very complex, requiring clinicopathological correlations and additional analyses. A deep insight into spongiosis pathogeny may open the perspectives of a classification refinement of autoimmune bullous dermatoses.

• eosinophilic spongiosis
• intraepidermal autoimmune bullous dermatoses
• neutrophilic spongiosis
• spongiotic reaction pattern
• subepidermal autoimmune bullous dermatoses

• antibody
• autoimmune blistering disease
• desmocollin
• desmoglein
• pemphigus
• systematic review

• Acantholysis
• Animals
• Autoantibodies/metabolism
• Autoimmunity
• Desmocollins/immunology
• Desmogleins/immunology
• Eosinophils/immunology
• Humans
• Neutrophils/immunology
• Pemphigus/immunology
• Phenotype
• Skin/immunology

• PTLD
• antibodies
• children
• intestine transplant
• liver
• malignancy
• organ transplantation
• paraneoplastic pemphigus

Eosinophilic spongiosis is a histological feature shared by some distinct inflammatory disorders, and is characterized by the presence of intraepidermal eosinophils associated with spongiosis. Most often, isolated eosinophilic spongiosis indicates the early stages of a subjacent autoimmune bullous dermatosis, such as the pemphigus group and bullous pemphigoid. Herein, the main causes of eosinophilic spongiosis are discussed, as well as the supplementary investigation needed to elucidate its etiology.

• Diagnosis, differential
• Eosinophils
• Pemphigoid, bullous
• Pemphigus
• Skin diseases, vesiculobullous

• ELISA
• autoantibody
• autoimmune bullous dermatosis
• biochip
• indirect immunofluorescence
• pemphigoid
• pemphigus
• serology

• Geographic tongue
• Lichen planus
• Pemphigoid
• Pemphigus
• Pyostomatitis vegetans

Pemphigus represents a group of autoimmune blistering diseases caused by autoantibodies against desmogleins (Dsgs), a class of desmosomal cadherins. Recently, several pemphigus patients only with desmocollin (Dsc) 3-specific antibodies have been reported. Here, we report a case of pemphigus herpetiformis (PH), where only anti-Dsc3-specific antibodies but not anti-Dsg antibodies were detected. A 76-year-old woman presented with a 3-year history of blister formation. Physical examination revealed pruritic erythemas with vesicles on the trunk and legs, but no lesions of the oral mucosa. A skin biopsy specimen revealed intraepidermal blister containing neutrophils, eosinophils, and lymphocytes. Direct immunofluorescence (IF) showed immunoglobulin G (IgG) and complement 3 (C3) depositions on the keratinocyte cell surfaces. Indirect IF showed IgG anti-keratinocyte cell surface antibodies. These findings hinted at a diagnosis of pemphigus. However, repeated enzyme-linked immunosorbent assays (ELISAs) for both anti-Dsg1 and 3 antibodies proved to be negative. Immunoblotting of normal human epidermal extracts revealed Dsc antibodies, and recently established ELISAs using human Dsc1-Dsc3 recombinantly expressed in mammalian cells detected anti-Dsc3 antibodies. Based on these clinical, histopathological, and immunological findings, the patient was diagnosed as PH with only anti-Dsc3 antibodies. Treatment with corticosteroid prednisolone and steroid-sparing agent dapsone accomplished complete clinical remission of the patient.

• Anti-desmocollin 3 antibody
• Pemphigus herpetiformis

Pseudopemphigoid can cause a chronic cicatricial conjunctivitis that is clinically identical to the manifestations seen in mucous membrane pemphigoid, a disorder with a common clinical phenotype and multiple autoimmune links. For the purpose of this review, we will describe pseudopemphigoid as caused by topical drugs, the most common etiology with ocular manifestations, and as caused by the pemphigus disease, a more rare etiology. Specifically, we will discuss the ophthalmological features of drug-induced cicatricial conjunctivitis, pemphigus vulgaris, and paraneoplastic pemphigus. Other etiologies of pseudopemphigoid exist that will not be described in this review including autoimmune or inflammatory conditions such as lichen planus, sarcoidosis, granulomatosis with polyangiitis (Wegener’s granulomatosis), erythema multiforme (minor, major, and Stevens-Johnson syndrome), bullous pemphigoid, skin-dominated linear IgA bullous dermatosis, and skin-dominated epidermolysis bullosa acquisita. Prompt diagnosis of the underlying etiology in pseudopemphigoid is paramount to the patient’s outcome as certain diseases are associated with a more severe clinical course, increased ocular involvement, and differential response to treatment. A complete history and ocular examination may find early cicatricial changes in the conjunctiva that are important to note and evaluate to avoid progression to more severe disease manifestations. When such cicatricial changes are noted, proper diagnostic techniques are needed to help elucidate a diagnosis. Lastly, collaboration between ophthalmologists and subspecialists such as dermatologists, pathologists, immunologists, and others involved in the care of the patient is needed to ensure optimal management of disease.

• Pseudopemphigoid
• Mucous membrane pemphigoid
• Cicatricial conjunctivitis
• Pemphigus vulgaris
• Paraneoplastic pemphigus
• Drug-induced conjunctival cicatrization