Axillary Freckling

Characterised by the intense and unusual freckling of the underarm and armpit area, Axillary Freckling is often a visual indicator of a more extensive genetic disorder.

What is Axillary Freckling?

Axillary Freckling is part of a specific designation of freckles that are also known as skinfold freckling that occurs within the underarm and armpit of a child. These markings on the skin are a particular part of the onset of freckling in the folds of a child’s body. These distinct freckles are present in children who have Neurofibromatosis, and appear most commonly in the following areas:

  • The armpit
  • The groin
  • The neck fold

The appearance of these freckles are a clear indicator of Neurofibromatosis, and alongside other symptoms can be used to diagnose the disease. Axillary Freckling is the freckling within the underarm and armpit area specifically. This freckling, in combination with the above two areas, is seen in more than 90% of children with NF1 by the age of 6, making it a reliable and clear indicator of this condition.

Axillary Freckling, despite being distinct due to its location, as well as being more intense in appearance, is the same as standard freckling, which is most commonly found on the limbs and the face of children and adults. The distinction of freckling within the armpit and underarm is specified by the use of the word ‘Axillary.’ As with all other freckles, Axillary Freckling is a cluster or scattering of melanized, darker skin cells that often appear in bulk.

Freckles are biologically distinct from moles or other darkening of the skin, and often can be formed through exposure to UV light or sunlight. In the case of Axillary Freckling, this is a rare location for freckles that is not caused by UV exposure, due to the areas in which they are located. This also applied to the freckles within the groin area that are also indicators of Neurofibromatosis.

Axillary Freckling is used by doctors and other medical professionals as a specific symptom of the Neurofibromatosis condition and is visible in almost every case of this condition.

Another medical term for Axillary Freckles is the Crowe sign, named after the dermatologist who recognized the importance of this skin condition in diagnosing NF1. Based on his research, we're aware that 20-30% of children with NF1 also had this unique distribution of freckles, and the appearance of this specific condition was not present in children without this illness.

Causes of Axillary Freckling

The appearance of both Axillary Freckling and other fold freckling is a direct symptom of the condition Neurofibromatosis, or NF1. However, it can also be an indicator of other severe health conditions, including but not limited to:

  • Turcot syndrome
  • Addison’s Disease
  • Noonan Syndrome
  • Optic Glioma
  • Unilateral Hyperhidrosis
  • Malignancy
  • Leopard Syndrome

Of all the conditions that cause the appearance of Axillary Freckling, Neurofibromatosis is the most common. However, a doctor or medical professional will be able to combine all of the symptoms of someone with this freckling along with a variety of other indicators or symptoms to create an informed judgment and opinion of what the Axillary Freckling on a patient indicates.

The physical appearance/symptoms of Axillary Freckling

As with all other freckling, Axillary Freckling can vary according to the person it appears on. For example, this condition may be less visible on dark skin, and the concentration and amount of freckles can vary on a per-person basis. Axillary Freckling appears like the majority of other freckling does, as darker patches of skin or cells that are often clustered together. However, the intensity and quantity of the freckling are very apparent in comparison to standard freckles.

One way in which these freckles can vary physically to normal freckles often present in children is that they are not influenced by the presence of UV light, and will not get darker or lighter as a result of the level of exposure to sunlight. Because of this, the appearance of the freckles will remain the same all year round.

In some cases, in children with a large number of freckles across their whole body, freckles may be present in and around the underarms that are not considered Axillary Freckling, as they are not a symptom of a significant condition or illness.

It is advised that even with highly freckled children, consulting with a doctor should be considered to confirm the kinds of freckles your children have under their arms. This is especially the case in young children who have new freckles where there weren’t any previously.

When does Axillary Freckling appear?

In general, Axillary Freckling manifests in children around the age of 6 and often accompanies other symptoms of illnesses such as Neurofibromatosis. These other symptoms may include cafe au lait patches or spots, also known as a macule, that are present from birth. It is likely that these freckles will be highly visible when the arms are lifted, and there is a significant concentration in and around the armpit area, especially apparent if the child is not freckled elsewhere.

Axillary Freckling may be present in children as young as two, or may not manifest until puberty, at which time it will likely be accompanied by other symptoms for a doctor to make an informed diagnosis for any conditions related to the appearance of freckling.

Treating Axillary Freckling

Axillary Freckling, in itself, is not a condition that can be directly treated. As with other permanent moles, freckles or birthmarks, even once your child or yourself has been diagnosed with a disorder relating to this condition, it is highly unlikely the freckles will ever disappear. This is because they are created directly within the melanin of the skin, and much like those with permanent freckles, there is not an easy way to get rid of them.

For those who choose to do so, however, the freckles could be covered with heavy duty or costume make-up, as this will not harm the skin in any way and provide a freckle-free appearance during the time the make-up is applied.

In comparison to the other conditions related to Neurofibromatosis, such as Neurofibromas, including papules and nodules which can be highly visible, Axillary Freckling is in a location that is easy to disguise and does not require any further treatment.

In regards to the reduction of Axillary Freckling due to curing Neurofibromatosis, there is no cure for this condition. Treatment may include anything from surgery to remove growths to chemotherapy and pain management, but none of these treatments will reduce or remove the existing freckling.

Neurofibromatosis and Axillary Freckling

As a genetic disorder of the nervous system, Neurofibromatosis, the leading case of Axillary Freckles, affects the development and growth of the body’s cell tissues. The freckles are associated with NF1, the more common form of this disorder. Alongside cafe au lait spots (patches of darker skin), small tumors and bone deformation, Axillary Freckles are a good indicator of this condition.

Other related symptoms may be:

  • Growths within the iris
  • Twisting of the spine
  • Nerve-related aches and pains
  • Tumors on the optic nerve

To receive a formal diagnosis of NF1, two or more of the following conditions must be present:

  • Six or more cafe au lait spots larger than 1.5cm in teens and adults, or 0.5cm in children and babies
  • Two or more tumors known as neurofibromas
  • Freckling in the armpit or groin
  • A tumor on the optic nerve
  • Two or more Lisch nodules
  • Distinctive lesions or dysplasia
  • A first-degree (mother or father) relative with NF1

In this case, Axillary Freckles are one of only seven different conditions for this disorder. As such, the appearance of these freckles in a young child should be brought to the attention of a doctor as soon as possible, especially if you or your child are experiencing these new symptoms in addition to any of the above-listed criteria.

Can Axillary Freckling be prevented?

As an often predisposed condition that is indirectly influenced by UV or sunlight, the appearance of Axillary Freckling cannot be prevented or reduced, beyond the temporary covering through clothing or make-up. As a genetic disorder, and the most likely cause of this condition, Neurofibromatosis cannot be prevented. As a symptom of this larger condition, Axillary Freckling can provide an early warning sign that can allow earlier and better treatment of the NF1 condition.