Dermatitis herpetiformis

Lesions have epidermal bullae REF: Fitzpatrik dermatology 6^th ed p. 558-73

Dermatitis herpetiformis (DH) is an intensely pruritic, papulovesicular skin disease characterized by lesions symmetrically distributed over extensor surfaces (i.e., elbows, knees, buttocks, back, scalp, and posterior neck).

Almost all DH patients have an associated, usually subclinical, gluten-sensitive enteropathy , and >90% express the HLA-B8/DRw3 and HLA-DQw2 haplotypes. DH may present at any age, including childhood; onset in the second to fourth decades is most common. The disease is typically chronic.

Biopsy:

Small intestine shows partial villus atrophy

Skin lesions show sub-epidermal bullae and papillary tip abscess , IgA in papillary tips (on DIF) Treatment:

Dapsone and gluten free diet

The condition described is dermatitis herpetiformis, which is strongly associated with gluten-sensitive enteropathy (celiac sprue), and often has a life-long, intermittent course.

Clinically, patients have (excoriated) groups of papules and vesicles on an erythematous base.

The lesions tend to involve the extensor surfaces of the extremities and the buttocks.

Microscopically, the lesions show subepidermal papillary dermal neutrophilic abscesses, with granular deposits of IgA and C3 in dermal papillary tips. Patients may respond dramatically to dapsone therapy.

sensitive enteropathy. In this condition absorption of gluten induces the formation of circulating immune complexes which deposit in the dermal papillae causing inflammation and dermoepidermal split. 

All patients with celiac disease express the HLA-DQ2 or HLA-DQ8 allele, though only a minority of people expressing DQ2/DQ8 have celiac disease. Absence of DQ2/DQ8 excludes the diagnosis of celiac disease

Celiac disease is associated with dermatitis herpetiformis (DH). Patients with DH have characteristic papulovesicular lesions that respond to dapsone. Almost all patients with DH have histologic changes in the small intestine consistent with celiac disease. In contrast, relatively few patients with celiac disease have DH.

A.i.e. Dermatitis herpetiformis

IgG deposits on Keratinocyte surface (i.e in intercellular spaces of epidermis) in fish net patternQ is seen in pemphigus.

– Linear IgG deposits along epidermal basement membrane (at dermo-epidermal junction) Q is seen in bullous

pemphigoid.

Granular IgA deposits in dermal papillae & EBMQ is seen in dermatitis herpetiformis and around small blood vessels in skin, intensive & kidney is seen in HS purpura. Whereas linear (not granular) IgA deposits along EBM is seen in linear IgA disease.

C i.e. HLA B8

D i.e. Dermatitis herpetiformis

A. i.e. Gluten free diet with minerals and vitamins

Dermatitis herpetiformis is associated with subclinical gluten sensitive enteropathy and HLA B8 halotypeQ. It presents with severely pruritic (itchy) papulovesicular/urticarial lesions and crusted papules & excoriation symmetrically distributed over extensor surfaces (i.e. elbows, knees, buttocks, back, scalp & posterior neck) Q.

On DIM, there is granular deposition of IgA autoantibodies (directed against epidermal transglutaminase) in papillary dermis (dermal papilla) and epidermal basement membrane (dermo-epidermal junction). Strick gluten free diet, Atkins diet and elemental diet is treatment of choice and dapsone is drug of choiceQ.

Answer is A (Dermatitis Herpetiformis)

Celiac disease is associated with Dermatitis Herpetiformis

Dermatitis Herpetiformis is regarded as cutaneous variant of celiac disease. Almost all patients with dermatitis N as Herpetiformis have evidence of celiac disease on intestinal biopsy’ – CMD

Associations of Celiac Disease (CMDT & Harrisons)

• Dermatitis Herpetiformis
• Other autoimmune disease including: (CMDT)

– Addison’s disease

–  Grave’s disease Diabetes mellitus- Type I (Harrisons)

– Myaesthenia Gravis

– Slogren syndrome

– Atrophic Gastritis

– Pancreatic insufficiency

• IgA deficiency (Harrisons)
• Lymphomas (Harrisons)

Note

Celiac disease is associated with an increased risk of cancer including Lymphomas (NHL, Intestinal T cell Lymphoma)

The possibility of Lymphoma must be considered whenever a patient with celiac sprue previously doing well on a gluten free diet is no longer responsive to gluten free diet’ – Harrisons

Ans. D: Ulcerative Colitis

These include insulin-dependent diabetes mellitus, thyroiditis, autoimmune hepatitis, SjOgren’s syndrome, Addison’s disease, atrophic gastritis and alopecia areata.

They may also be affected by conditions that are not related to gluten intolerance.

These include IgA deficiency, psoriasis, Down s^yndrome and primary biliary cirrhosis.

Non-Hodgkin’s lymphoma, affecting the intestines or any part of the body, is a serious complication of gluten enteropathy but is fortunately rare, affecting less than 1% of patients.

The range of conditions less commonly induced by gluten also includes:

• Neurological problems including ataxia (loss of balance), polyneuropathy, epilepsy
• Heart problems including pericarditis and cardiomyopathy
• Thin dental enamel
• Recurrent abortions (miscarriage)
• Fatty liver resulting in abnormal liver function
• Aphthous ulcers

Ans. C: Dapsone

Dermatitis herpetiformis:

• Epidemiology: Rare, male to female ratio is 2:1, onset at 20 to 40 years of age, but also in children, whites, rare in blacks or Asians
• Features: Grouped (herpetiform) excoriations or vesicles symmetrically located on extensor remission; watch for signs surfaces of elbows, knees, sacrum, buttocks, and shoulders with intense pruritus and burning sensation
• Diagnosis:

– Light microscopy: neutrophilic abscesses in dermal papillae, dermal infiltrates of neutrophils and eosinophils with subepidermal vesicles.

– Direct Immunoflorescence: granular IgA deposits in the tips of the dermal papillae

• Management: Gluten-free diet; sulfones.

Patients will experience prompt relief of lesions within one to two days of initializing treatment with dapsone or sulfapyridine.

It is important to remember to always check glucose-6-phosphate dehydrogenase (G6PD) and baseline complete blood count levels before starting dapsone, followed by complete blood cell counts every month to monitor for signs of hemolytic anemia.

Watch for signs of other autoimmune disorders; may coexist with gluten-sensitive enteropathv