1.5.6 Prurigo Simplex
Grading & Level of Importance: B
Rather common disease, standing alone or associated with atopic dermatitis.
Group of dermatoses with many causes, all featuring intense pruritus followed by reactive crusted papules (prurigo = itchy crust).
Aetiology & Pathogenesis
Prurigo seems to develop in individuals, who overreact to pruritus (itch).
Causes: systemic triggers of pruritus, idiopathic, atopic constitution. Chronic, persistent disease with proliferation of peripheral sensory nerves.
Prurigo simplex and prurigo nodularis seem to be different stages of a common disease.
Signs & Symptoms
Pruritus, small sero-papules (beginning) and excoriations with symmetrical distribution of secondary prurigo lesions on the extensor surfaces of the extremities, neck, lower trunk, and buttocks. Typically, patients present with widespread dome shaped papules, which are intensely itchy leading to sleep deprivation.
Extremities, trunk (interscapular area is usually spared!).
Acute, subacute and chronic forms.
Laboratory & other workups
Exclude underlying metabolic diseases, malfunctions of kidney and liver, hematologic disorders and parasitic infestations. Blood: Eosinophils, IgE (DD: prurigo type of atopic dermatitis). Psychological/psychiatric consultation recommended (67% abnormal).
Acute to chronic dermatitis with epidermal acanthosis and spongiosis, strong inflammatory cell infiltrate. Sensory nerve proliferation.
Chronic, symptoms often persist for months to years.
Superinfections of excoriated lesions.
Prevention & Therapy
Secondary prevention: Exclude underlying disorders and avoid scratching.
- Topical: corticosteroids, capsaicin cream, narrow band UVB, PUVA
- Systemic: sedative antihistamines. In prurigo type of atopic dermatitis: Dupilimumab.
Be the first one to leave a comment!