A 2.5 Year Old Small Boy with Itchy Skin Symptoms Treated for Atopic Dermatitis

The 2.5 year old boy presented with an itchy skin rash above the elbows, knees and buttocks. He had been treated for atopic dermatitis, but did not improve. Since the distribution of the symptoms suggested dermatitis herpetiformis (DH), we performed immunofluorescence from the perilesional skin and could confirm the diagnosis by the characteristic IgA staining in the dermal papilla (Fig. 15.1) and by the endomysium antibody (EMA) positivity, diagnostic for celiac disease (CD) (that time no transglutaminase (TG) 2 or 3 ELISAs were available) [1]. He also underwent a small bowel biopsy by Crosby capsule and showed mild partial villous atrophy and a pathologic IgA staining in the jejunum [2]- today recognized as TG2 bound IgA staining- and was treated by gluten free diet (GFD) and by low dose dapsone. While there were no laboratory side effects from the drug detected, his steps became uncertain, and could not run as before. When we stopped the medication his movement recovered. He went on solely with the GFD and his skin became symptom-free. Several years later the patient’s father developed severe weight loss and was treated for anorexia nervosa. He asked us whether we could check him for CD, since he did not feel the psychological urge to hunger, but suffered from recurrent diarrhea. He was diagnosed with an acute CD. That time, his other son was also investigated for gluten sensitivity and he was also EMA positive, and had mild partial villous atrophy on jejunal biopsy. The mother was not affected by the disease, and none of the family members had associated diseases at that time.

Figure 15.1
figure 1

IgA granules within the papillary dermis

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Key Points to Case 1

  1. 1.

    DH can develop at any age, rarely in the very young, or in very elderly too

  2. 2.

    Dapsone can induce temporary neuropathies, mostly in the older age group, and, as in this case, in the very young, too

  3. 3.

    Screening of immediate family members of DH patients for CD is necessary

A Young Male with “Well Treated”, Symptom-Free Celiac Disease Developed an Itchy, Crusted Skin Rash

This patient had a long history of coeliac disease (CD). The boy was diagnosed with acute CD within his first year of life and was treated by gluten-free diet (GFD) by the pediatric gastroenterology department. He had no further major medical problems before puberty when he felt unwell and different, and started to eat some gluten containing food when he was with friends or joined to companies. Although he was controlled for the CD, and he did not have clinical symptoms, he gradually developed an intermittent, itchy, commonly crusted, “allergic” rash above the elbows, buttocks, knees and above the shoulders. He was 18 when seen at the dermatology department with classical DH (Fig. 15.2), which was confirmed by skin histology and immunofluorescence. At that time his endomysium antibody (EMA) was positive. Under strict GFD he slowly became free of skin symptoms. There was no CD in the family by serological screening at that time, but anti-thyroid antibodies were identified in the patient without a functional endocrinological defect.

Figure 15.2
figure 2

Typical crusted erosions above the knees

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Key Points to Case 2

  1. 1.

    CD and DH are very closely related, as it is well illustrated with this case report. This case also demonstrates, that there are no genetic differences between the two diseases [4]. Severe CD is usually not associated with DH, mostly mild gluten induced enteropathy can induce the skin disease.

  2. 2.

    Associated other autoimmunities such as autoimmune thyroiditis, vitiligo, autoimmune diabetes mellitus or pernicious anemia are commonly associated with DH [3].

  3. 3.

    According to our current knowledge, strict GFD should be kept life-long.

Discussion

Dermatitis herpetiformis is unique within the group of autoimmune blistering diseases [1], because it is a gluten induced, reversible autoimmunity to transglutaminase 3 and 2 (TG3 and TG2) in the vast majority of the patients. Histologically it is characterized by granular IgA, complement 3 and TG 3 deposition in the perilesional papillary dermis, while within the skin symptoms also a subepidermal neutrophil accumulation and blister formation is present. Since neither the circulating IgA TG3 nor the IgA TG2 type autoantibodies bind along the dermal connective tissue of the normal papillary skin, the cutaneous disease is most probably of immune complex origin. DH is developing mainly among people with mild, latent form of CD and can be well treated by a life-long lasting, strict GFD. The time to complete skin remission, however, can last months, or longer. Under GF diet both the IgA type TG2 and TG3 autoantibodies gradually disappear from the circulation. CD and DH patients have a common genetic predisposition, best characterized by the HLA DQ2 (95 %) or HLADQ8 (5 %) haplotypes [4].