Table 1.

A proposed systematics of skin diseases from the spectrum of dermatitis and eczema (SoDE).

Etiopathology Classes	Examples of Clinical Diagnoses 1
No known/detectable triggers	Intrinsic atopic dermatitis (endogenous eczema)
Triggered by exogenous factors without the involvement of specific hypersensitivity	Irritant contact dermatitis Winter dermatitis (hand, foot, and generalized) Microtrauma dermatitis Friction dermatitis Phototoxic dermatitis Radiodermatitis (radiation dermatitis) Seborrheic dermatitis
Triggered by exogenous factors with the involvement of specific immunological hypersensitivity	Extrinsic atopic dermatitis (exogenous eczema) Allergic contact dermatitis SDRIFE/SRACD 2 Photoallergic dermatitis Protein contact dermatitis
Autoimmune reactions	Autoimmune dermatitis, including: Autoimmune progesterone dermatitis Autoimmune estrogen dermatitis
Homeostatic imbalance	Stasis dermatitis Deficiency dermatitis

¹ Some clinical diagnoses may overlap, while others may be divided between classes because of their heterogeneity. ² SDRIFE (symmetric drug-related intertriginous and flexural exanthema) and SRACD (systemic reactivation of allergic contact dermatitis) are both variants of ACD in which haptens enter the body through a non-cutaneous route (ingestion, inhalation, or injection) and are further distributed via blood circulation into the skin where they ultimately cause an allergic reaction [17,20,21].