Class A antibodies (IgA) deposit in the gut. Some may bind to the CD89 (FcαRI) receptor on macrophages (M1) via their Fc region (constant region). This will trigger endocytosis of the tTG-IgA complex, resulting in the activation of macrophages. Macrophages secrete more IL-8, propagating the neutrophil-mediated inflammatory response. The purportedly cross-reactive autoantibodies may migrate to the skin in dermatitis herpetiformis. IgA deposits may form if the antibodies cross-react with epidermal transglutanimase (eTG). Some patients have eTG-specific antibodies instead of tTG-specific cross-reactive antibodies and the relationship between dermatitis herpetiformis and celiac disease in these patients is not fully understood. Macrophages may be stimulated to secrete IL-8 by the same process as is seen in the gut, causing neutrophils to accumulate at sites of high eTG concentrations in the dermal papillae of the skin. Neutrophils produce pus in the dermal papillae, generating characteristic blisters. IL-31 accumulation at the blisters may intensify itching sensations. Memory B and T cells may become activated in the absence of PAMPs and DAMPs during successive encounters with tTG-modified gliadin complexes or modified gliadin alone, respectively. Symptoms of dermatitis herpetiformis are often resolved if patients avoid a gluten-rich diet. Diagnosis
Dermatitis herpetiformis often is misdiagnosed, being confused with drug eruptions, contact dermatitis, dishydrotic eczema (dyshidrosis), and even scabies. Other diagnoses in the differential diagnosis include bug bites and other blistering conditions such as bullous pemphigoid, linear IgA bullous dermatosis, and bullous systemic lupus erythematosus.
Six or more spots of at least 5mm in diameter in pre-pubertal children and at least 15mm in post-pubertal individuals is one of the major diagnostic criteria for NF1. Prognosis
Café au lait spots are usually present at birth, permanent, and may grow in size or increase in number over time.Cafe au lait spots are themselves benign and do not cause any illness or problems. However, they may be associated with syndromes such as Neurofibromatosis Type 1 and McCune-Albright syndrome.The size and shape of the spots can vary in terms of description. In Neurofibromatosis Type 1, the spots tend to be described as ovoid, with smooth borders. In other disorders, the spots can be less ovoid, with jagged borders. In Neurofibromatosis Type 1, the spots tend to resemble the "coast of California," rather than the "coast of Maine," meaning the edges are smoother and more linear. Treatment
Café au lait spots can be removed with lasers. Results are variable as the spots are often not completely removed or can come back after treatment. Often, a test spot is treated first to help predict the likelihood of treatment success. See also
Birthmark
Nevus
List of cutaneous conditions
List of conditions associated with café au lait macules

References
External links

eMedicine